Human-computer interface system

ABSTRACT

One variation of a system includes a substrate including: a first layer including a first spiral trace coiled in a first direction; a second layer arranged below the first layer and including a second spiral trace coiled in a second direction and cooperating with the first spiral trace to form a multi-layer inductor; and a sensor layer including an array of drive and sense electrode pairs. The system also includes: a cover layer arranged over the substrate and defining a touch sensor surface; and a first magnetic element arranged below the substrate and defining a first polarity facing the multi-layer inductor. The system further includes a controller configured to drive an oscillating voltage across the multi-layer inductor to oscillate the substrate in response to detecting an input on the touch sensor surface based on electrical values from the set of drive and sense electrode pairs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/367,572, filed on 5 Jul. 2021, and Ser. No. 17/367,576, filed on 5Jul. 2021, each of which claims priority to U.S. Provisional ApplicationNo. 63/048,071, filed on 3 Jul. 2020, which is incorporated in itsentirety by this reference.

U.S. patent application Ser. Nos. 17/367,572 and 17/367,576 are each acontinuation-in-part application of U.S. patent application Ser. No.17/191,631, filed on 3 Mar. 2021, which claims the benefit of U.S.Provisional Patent Application Nos. 62/984,448, filed 3 Mar. 2020,63/040,433, filed on 17 Jun. 2020, and 63/063,168, filed on 7 Aug. 2020,each of which is incorporated in its entirety by this reference.

U.S. patent application Ser. Nos. 17/367,572 and 17/367,576 are each acontinuation-in-part application of U.S. patent application Ser. No.17/092,002, filed on 6 Nov. 2020, which is a continuation application ofU.S. patent application Ser. No. 16/297,426, filed on 8 Mar. 2019, whichclaims the benefit of U.S. Provisional Application No. 62/640,138, filedon 8 Mar. 2018, each of which is incorporated in its entirety by thisreference.

U.S. patent application Ser. No. 16/297,426 is also acontinuation-in-part application of U.S. patent application Ser. No.15/845,751, filed on 18 Dec. 2017, which is a continuation-in-partapplication of U.S. patent application Ser. No. 15/476,732, filed on 31Mar. 2017, which claims the benefit of U.S. Provisional Application No.62/316,417, filed on 31 Mar. 2016, and U.S. Provisional Application No.62/343,453, filed on 31 May 2016, each of which is incorporated in itsentirety by this reference.

This application is also related to U.S. patent application Ser. No.14/499,001, filed on 26 Sep. 2014, and to U.S. patent application Ser.No. 17/191,631, filed on 3 Mar. 2021, each of which is incorporated inits entirety by this reference.

TECHNICAL FIELD

This invention relates generally to the field of touch sensors and morespecifically to a new and useful human-computer interface system in thefield of touch sensors.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of a system;

FIG. 2 is a schematic representation of one variation of the system;

FIG. 3 is a schematic representation of one variation of the system;

FIGS. 4A and 4B are flowchart representations of variations of thesystem;

FIGS. 5A and 5B are flowchart representations of one variation of thesystem;

FIG. 6 is a schematic representation of one variation of the system;

FIG. 7 is a schematic representation of one variation of the system;

FIG. 8 is a schematic representation of one variation of the system;

FIGS. 9A and 9B are schematic representations of one variation of thesystem;

FIGS. 10A and 10B are schematic representations of one variation of thesystem;

FIGS. 11A-11D are schematic representations of one variation of thesystem;

FIG. 12 is a schematic representation of one variation of the system;

FIG. 13 is a schematic representation of one variation of the system;

FIG. 14 is a schematic representation of one variation of the system;

FIGS. 15A-15C are schematic representations of one variation of thesystem;

FIG. 16 is a flowchart representation of one variation of the system;

FIG. 17 is a flowchart representation of one variation of the system;

FIG. 18 is a flowchart representation of one variation of the system;

FIG. 19 is a flowchart representation of one variation of the system;

FIG. 20 is a schematic representation of one variation of the system;

FIG. 21 is a schematic representation of one variation of the system;

FIG. 22 is a flowchart representation of one variation of the system;and

FIG. 23 is a schematic representation of one variation of the system.

DESCRIPTION OF THE EMBODIMENTS

The following description of embodiments of the invention is notintended to limit the invention to these embodiments but rather toenable a person skilled in the art to make and use this invention.Variations, configurations, implementations, example implementations,and examples described herein are optional and are not exclusive to thevariations, configurations, implementations, example implementations,and examples they describe. The invention described herein can includeany and all permutations of these variations, configurations,implementations, example implementations, and examples.

1. System

As shown in FIG. 1, a system 100 includes: a substrate 102; a coverlayer 170; a first magnetic element 181; and a controller 190. Thesubstrate 102 includes: a first layer 110 including a first spiral trace111 coiled in a first direction; a second layer 120; and a sensor layerincluding an array of drive and sense electrode pairs 105. The secondlayer 120: is arranged below the first layer 110; and includes a secondspiral trace 122 coiled in a second direction opposite the firstdirection, coupled to the first spiral trace 111 by a via between thefirst layer no and the second layer 120, and cooperating with the firstspiral trace 111 to form a multi-layer inductor 150. The cover layer 170is arranged over the substrate 102 and defines a touch sensor surface172. The first magnetic element 181 is arranged below the substrate 102and defines a first polarity facing the multi-layer inductor 150. Thecontroller 190 is configured to: read a set of electrical values fromthe set of drive and sense electrode pairs 105; detect a first input onthe touch sensor surface 172 based on the set of electrical values; and,in response to detecting the first input, drive an oscillating voltageacross the multi-layer inductor 150 to induce alternating magneticcoupling between the multi-layer inductor 150 and the first magneticelement 181 and oscillate the substrate 102 and the cover layer 170relative to the chassis 192.

One variation of the system 100 shown in FIG. 2 includes: a substrate102; a cover layer 170; a set of deflection spacers 160; a firstmagnetic element 181; and a controller 190. In this variation, thesubstrate 102 defines a unitary structure and includes a first layer110, a second layer 120, and a bottom layer 140. The first layer 110: isarranged below the top layer 104; and includes a first spiral trace 111coiled in a first direction and defining a first end and a second end.The second layer 120: is arranged below the first layer no; and includesa second spiral trace 122 coiled in a second direction opposite thefirst direction, defining a third end and a fourth end, the third endelectrically coupled to the second end of the first spiral trace in, andcooperating with the first spiral trace 111 to form a multi-layerinductor 150 defining a primary axis. The bottom layer 140: is arrangedbelow the second layer 120 opposite the first layer no; and includes aset of sensor traces 146 located proximal a perimeter of the substrate102. The set of deflection spacers 160 is coupled to the second set ofsensor traces 146 and supports the substrate 102 on a chassis 192 of adevice. The cover layer 170 is arranged over the substrate 102 oppositethe set of deflection spacers 160 and defines a touch sensor surface172. The first magnetic element 181: is arranged in the chassis 192below the substrate 102; defines a first polarity facing the multi-layerinductor 150; and extends parallel to the primary axis of themulti-layer inductor 150. The controller 190 is configured to: read aset of electrical values from the set of sensor traces 146; interpret aforce magnitude of a first input on the touch sensor surface 172 basedon the set of electrical values; and, in response to detecting the forcemagnitude exceeding a threshold force, drive an oscillating voltageacross the multi-layer inductor 150 during a haptic feedback cycle toinduce alternating magnetic coupling between the multi-layer inductor150 and the first magnetic element 181 and oscillate the substrate 102and the cover layer 170 relative to the first magnetic element 181.

Yet another variation of the system 100 shown in FIG. 3 includes: asubstrate 102; a cover layer 170; a first magnetic element 181; a secondmagnetic element 182; and a controller 190. In this variation, thesubstrate 102 defines a unitary structure and includes a top layer 104,a first layer no, and a bottom layer 140. The top layer 104 includes anarray of drive and sense electrode pairs 105. The first layer no: isarranged below the top layer 104; and includes a first spiral trace 111coiled in a first direction and defining a first end and a second end.The second layer 120: is arranged below the first layer no opposite thetop layer 104; and includes a second spiral trace 122 coiled in a seconddirection opposite the first direction, defining a third end and afourth end, the third end electrically coupled to the second end of thefirst spiral trace in, and cooperating with the first spiral trace 111to form a multi-layer inductor 150 defining a primary axis and asecondary axis. The cover layer 170 is arranged over the top layer 104and defines a touch sensor surface 172. The first magnetic element 181:is arranged below the substrate 102; defines a first polarity facing themulti-layer inductor 150; extends along the primary axis of themulti-layer inductor 150; and is arranged on a first side of the primaryaxis of the multi-layer inductor 150. The second magnetic element 182:is arranged below the substrate 102 adjacent the first magnetic element181; defines a second polarity, opposite the first polarity, facing themulti-layer inductor 150; extends along the primary axis of themulti-layer inductor 150; and is arranged on a second side of theprimary axis of the multi-layer inductor 150. The controller 190 isconfigured to: read a set of electrical values from the set of drive andsense electrode pairs 105; detect a first input on the touch sensorsurface 172 based on the set of electrical values; and, in response todetecting the first input, drive an oscillating voltage across themulti-layer inductor 150 during a haptic feedback cycle to inducealternating magnetic coupling between the multi-layer inductor 150 andthe first magnetic element 181 and the second magnetic element 182 andoscillate the substrate 102 and the cover layer 170 relative to thefirst magnetic element 181 and the second magnetic element 182.

Another variation of the system 100 includes: a substrate 102; a firstmagnetic element 181; and a controller 190. In this variation, thesubstrate 102 defines a unitary structure and includes: a first layercomprising a first spiral trace, coiled in a first direction, anddefining a first end and a second end; a second layer arranged below thefirst layer and comprising a second spiral trace, coiled in a seconddirection opposite the first direction defining a third end electricallycoupled to the second end of the first spiral trace, defining a fourthend, and cooperating with the first spiral trace to form a multi-layerinductor defining a primary axis and a secondary axis. The firstmagnetic element: is arranged below the substrate; defines a firstpolarity facing the multi-layer inductor; extends along the primary axisof the multi-layer inductor; and is arranged on a first side of theprimary axis of the multi-layer inductor. The second magnetic element:is arranged below the substrate adjacent the first magnetic element;defines a second polarity, opposite the first polarity, facing themulti-layer inductor; extends along the primary axis of the multi-layerinductor; and is arranged on a second side of the primary axis of themulti-layer inductor. The controller is configured to, in response to aninput on a touch sensor surface arranged over the substrate, drive anoscillating voltage across the multi-layer inductor during a hapticfeedback cycle to: induce alternating magnetic coupling between themulti-layer inductor and the first magnetic element and the secondmagnetic element; and oscillate the substrate relative to the firstmagnetic element and the second magnetic element.

Yet another variation of the system 100 includes: a substrate 102; a setof deflection spacers 160; an array of spring elements; a first magneticelement 181; and a controller 190. In this variation, the substrate 102defines a substrate defining a unitary structure and comprising: a firstlayer comprising a first spiral trace coiled in a first direction anddefining a first end and a second end; and a bottom layer arranged belowthe first layer and comprising a second spiral trace coiled in a seconddirection opposite the first direction, defining a third endelectrically coupled to the second end of the first spiral trace,defining a fourth end, and cooperating with the first spiral trace toform a multi-layer inductor defining a primary axis. The set ofdeflection spacers, each deflection spacer in the set of deflectionspacers arranged over a discrete deflection spacer location, in a set ofdiscrete deflection spacer locations, on the bottom layer of thesubstrate. The array of spring elements: couples the set of deflectionspacers to a chassis of a computing device; supports the substrate onthe chassis; and is configured to yield to oscillation of the substrate.The first magnetic element: is arranged in the chassis below thesubstrate; defines a first polarity facing the multi-layer inductor; andextends parallel to the primary axis of the multi-layer inductor. Thecontroller configured to, in response to an input on a touch sensorsurface arranged over the substrate, drive an oscillating voltage acrossthe multi-layer inductor during a haptic feedback cycle to: inducealternating magnetic coupling between the multi-layer inductor and thefirst magnetic element; and oscillate the substrate relative to thefirst magnetic element and against the set of spring elements.

2. Applications

As shown in FIGS. 1-3, the system 100 for human-computer interfacingincludes: a touch sensor; a multi-layer inductor 150; and a controller190. The touch sensor includes: a substrate 102; an array of drive andsense electrode pairs 105 patterned across the substrate 102; a coverlayer 170 defining a touch sensor surface 172; and a force-sensitivelayer 174 arranged between the substrate 102 and the cover layer 170 andincluding a material exhibiting changes in local contact resistance(and/or changes in local bulk resistance) responsive to changes in forcemagnitude applied to the touch sensor surface 172. As shown in FIGS. 8,9A, 10A, 10B, and 11A, 11B, 11C, and 11D, the substrate 102 is flexiblymounted within a receptacle 194 (e.g., a touchpad receptacle 194) of achassis 192 of a computing device to permit movement (i.e., oscillation,vibration) of the substrate 102 within the chassis 192 during a hapticfeedback cycle.

A set of magnetic elements are arranged within (e.g., rigidly coupledto, bonded to) a receptacle 194 (e.g., a touchpad receptacle 194) withinthe receptacle 194. A set of spiral traces are fabricated within each ofmultiple adjacent layers of the substrate 102—below the drive and senseelectrode pairs 105—and are connected by vias to form a multi-layerinductor 150 arranged over the magnetic elements.

During a scan cycle, the controller 190: reads electrical values fromthe drive and sense electrode pairs 105 during a scan cycle; andinterprets locations and force magnitudes of inputs on the touch sensorsurface 172 based on these electrical values. In response to detecting anew input—that exceeds a threshold force magnitude—on the touch sensorsurface 172, the controller 190: outputs a command based on a locationand/or force magnitude of the input; and selectively drives themulti-layer inductor 150 with an oscillating voltage (or oscillatingcurrent), which induces an alternating magnetic field through themulti-layer inductor 150, magnetically couples the multi-layer inductor150 to the magnetic elements, yields an alternating force between themulti-layer inductor 150 and the magnetic elements, and thus oscillatesthe substrate 102 and the touch sensor surface 172 relative to thechassis 192 of the device.

2.1 Integrated Induction Coil

In this variation, the multi-layer inductor 150 and the set of magneticelements can cooperate to form an integrated vibrator configured tooscillate the substrate 102 within the chassis 192. For example, themulti-layer inductor 150 can be formed by a set of planar coil tracesetched or fabricated on each of multiple layers within the substrate 102and interconnected by vias through these layers to form one continuousinductor with multiple turns, one or more cores, and/or one or morewindings arranged over the set of magnetic elements.

For example, the multi-layer inductor 150 can include: a first tracespiraling inwardly in a first wind direction on a bottom layer 140 ofthe substrate 102; a second trace spiraling outwardly in the first winddirection on a second layer 120 of the substrate 102; a third tracespiraling inwardly in the first wind direction on a third layer 130 ofthe substrate 102; and a fourth trace spiraling outwardly in the firstwind direction—between adjacent loops of the second trace—on the secondlayer 120 of the substrate 102. Vias can connect: the end of the firstspiral trace 111 in the first layer 110 to the start of the secondspiral trace 122 in the second layer 120; the end of the second spiraltrace 122 in the second layer 120 to the start of the third spiral trace133 in the third layer 130; the end of the third spiral trace 133 in thethird layer 130 to the start of the fourth spiral trace 144 in thesecond layer 120; and the end of the fourth spiral trace 144 in thesecond layer 120 to the bottom layer 140 near the start of the firstspiral trace 111.

Thus, in this example, the multi-layer inductor 150 can include multiplespiral traces spanning multiple layers of the substrate 102 andconnected to form a continuous inductive coil with two terminals fallingin close proximity (e.g., within two millimeters) on the bottom layer140 of the substrate 102.

The set of magnetic elements can be bonded, fastened, mounted, and/orintegrated, etc. into a chassis 192 of a device beneath the multi-layerinductor 150 and can magnetically couple to the multi-layer inductor 150when a voltage is applied across the multi-layer inductor 150 by thecontroller 190. In particular, the controller 190 can supply anoscillating voltage (and therefore an alternating current) to themulti-layer inductor 150 (e.g., via a drive circuit coupled to andtriggered by the controller 190), which induces: an alternating magneticfield through the multi-layer inductor 150; induces alternating magneticcoupling between the set of magnetic elements and the multi-layerinductor 150; and thus oscillates the substrate 102.

2.2 Unitary Substrate with Integral Input and Output Components

Generally, in this variation, the system 100 functions as a touch sensorwith an integrated haptic actuator, pressure sensing, and shieldingwithin a thin (e.g., 4-millimeter-thick) package. For example, thesystem 100 can be installed in a touchpad receptacle 194 (hereafter the“receptacle 194”) in a laptop computer (shown in FIGS. 13, 14, 15A, 15B,and 15C), in a touchpad receptacle 194 in a peripheral user input device(shown in FIG. 16), or under a display of a tablet or smartphone.

As shown in FIGS. 5A, 5B, 6, and 7, the system 100 includes a thin(e.g., 2.5-millimeter-thick) substrate 102 that defines a suite of thin(or “2.5D”) traces that form: drive and sense electrodes of a touchsensor; drive and sense electrodes of a set of secondary force orpressure sensors; and an inductor configured to magnetically couple toan adjacent magnetic element. In particular, the multi-layer inductor150: is integrated into a substrate 102 in the form of multipleinterconnected spiral traces etched or otherwise fabricated acrossmultiple layers of the substrate 102; and is configured to magneticallycouple to a magnetic element integrated into (e.g., located within andretained by) a chassis 192. Thus, the set of magnetic elements and themulti-layer inductor 150 cooperate to function as a multi-layer inductor150 configured to oscillate a touch sensor surface 172 responsive topolarization of the multi-layer inductor 150 (e.g., by a drive circuitor controller 190), thereby enabling the system 100 to output real-timehaptic feedback in response to inputs on the touch sensor surface 172.

Therefore, the system 100 can include a set of planar, interconnectedspiral traces fabricated across multiple conductive (e.g., copper)layers of the substrate 102 to form a multi-layer inductor 150 locatedfully within the substrate 102 and fabricated concurrently with and withthe same processes as touch sensor electrode traces that form acapacitive or resistive touch sensor across a top of the substrate 102and that form a capacitive or resistive pressure sensor across a bottomof the substrate 102.

More specifically, a dense grid array of drive and sense electrode pairs105 can be concurrently fabricated across a top layer 104 of thesubstrate 102 to form a touch sensor configured to detect thex-position, the y-position, and/or a force magnitude of an input on thetouch sensor surface 172. Additionally or alternatively, a set of sensortraces 146 can be concurrently fabricated on a bottom layer 140 of thesubstrate 102 at intermittent locations about a perimeter of thesubstrate 102 to form a sparse array of force sensors configured todetect a force magnitude of an input on the touch sensor surface 172.The electrical traces that form these sensors can then therefore fallfully within the substrate 102. A thin cover layer 170 (e.g., a0.5-millimeter-thick glass or polymer panel for a capacitive touchsensor; a 0.5-millimeter-thick force-sensing layer for the resistivetouch sensor arrange across the top layer 104 of the substrate 102) canbe installed over the top layer 104 of the substrate 102 to enclose thetouch sensor and form a touch sensor surface 172. Force-sensing couponsand/or low-durometer spacers (e.g., with a total thickness of onemillimeter) can be installed over each sensor trace on the bottom of thesubstrate 102 to form a set of deflection spacers 160 configured tosupport the substrate 102 with the receptacle 194 of the substrate 102,to carry forces input on the touch sensor surface 172 into the chassis192, and to output signals corresponding to forces carried by theindividual sensor traces 146, which the controller 190 can convert intoindividual forces and total forces carried at these deflection spacers160 in response to inputs on the touch sensor surface 172. A thin,non-conductive, non-magnetic buffer layer (e.g., a polyimide film lessthan 0.2 millimeters in thickness) can be applied over the bottom spiraltrace of the multi-layer inductor 150 to maintain a minimal gap betweenthe multi-layer inductor 150 and the set of magnetic elements arrangedin the receptacle 194 below. Thus, the total height of the system 100with the cover layer 170 and the set of deflection spacers 160 may beless than 4 millimeters.

Furthermore, the chassis 192 of a device (e.g., a laptop computer, aperipheral input device) can define a shallow (e.g., 4-millimeter-deep)receptacle 194, and the system 100 can be installed in the receptacle194—with the deflection spacers 160 in contact with the base of thereceptacle 194—to enable touch sensing, pressure sensing, and hapticfeedback functionality in the device with no or limited increase inthickness of the chassis 192. In one implementation, the chassis 192 ofthe device further includes a cavity recessed below the receptacle 194,and the set of magnetic elements is installed (e.g., bonded, potted)within the cavity below the multi-layer inductor 150 on the substrate102. Alternatively, a thinner magnetic element (e.g., 0.8 mm inthickness) can be installed in the receptacle 194 between the base ofthe cavity and the bottom of the substrate 102 (e.g., between the baseof the cavity and the buffer layer arranged over the first spiral trace11 of the multi-layer inductor 150).

Therefore, the system 100—including the substrate 102, the touch sensor,and/or the deflection spacers 160, etc.—can seat low in the receptacle194 of the device with a small gap between the bottom layer 140 of thesubstrate 102 and the receptacle 194 (e.g., less than 300 microns ratherthan multiple millimeters to accommodate a discrete inductor installedon the substrate 102), thereby limiting total assembled height of thesystem 100 and the device. Furthermore, integration of the multi-layerinductor 150 into the substrate 102 may reduce and/or eliminatepossibility of fatigue or other damage to the multi-layer inductor 150resulting from repeated cycling and may enable a consistent offsetbetween the multi-layer inductor 150 and the set of magnetic elements,thereby enabling looser tolerances for vertical separation distancebetween the substrate 102 and the receptacle 194.

As described above and shown in FIGS. 13, 14, 15A, 15B, and 15C, thesystem 100 can be integrated into the chassis 192 of a computing device,such as a laptop computer, to form a force-sensitive trackpad orkeyboard surface configured to serve real-time haptic feedback to a userinterfacing with the computing device and to detect positions and/orforces of the inputs applied over the trackpad or keyboard surface.Additionally and/or alternatively, the system 100 can be integrated intoa portable electronic device—such as under the display of a smartphoneor smartwatch, or as a peripheral trackpad and/or keyboard device—inorder to enable real-time force sensing and haptic feedback capabilitieson these portable electronic devices, as shown in FIG. 16.

3. Substrate and Touch Sensor

As shown in FIGS. 6 and 12, the system 100 includes a substrate 102 thatincludes a set of (e.g., six) conductive layers etched to form a set ofconductive traces; a set of (e.g., five) substrate layers interposedbetween the stack of conductive layers; and a set of vias that connectthe set of conductive tracers through the set of substrate layers. Forexample, the substrate 102 can include a six-layer, rigid fiberglassPCB.

In particular, a top conductive layer and/or a second conductive layerof the substrate 102 can include a set of traces that cooperate to forman array (e.g., a grid array) of drive and sense electrode pairs 105within a touch sensor. Subsequent conductive layers of the substrate 102below the touch sensor can include interconnected spiral traces thatcooperate to form a single- or multi-core, single- or multi-winding,multi-layer inductor 150. Furthermore, a bottom conductive layer and/ora penultimate conductive layer of the substrate 102 can include a set ofinterdigitated electrodes distributed about the perimeter of thesubstrate 102 to form a sparse array of force sensors.

3.1 Resistive Touch Sensor

In one implementation, the first and second conductive layers of thesubstrate 102 include columns of drive electrodes and rows of senseelectrodes (or vice versa) that terminate in a grid array of drive andsense electrode pairs 105 on the top layer 104 of the substrate 102. Inthis implementation, the system 100 further includes a force-sensitivelayer 174: arranged over the top conductive layer of the substrate 102(e.g., interposed between the top layer 104 of the substrate 102 and thecover layer 170); and exhibiting local changes in contact resistanceacross the set of drive and sense electrode pairs 105 responsive tolocal application of forces on the cover layer 170 (i.e., on the touchsensor surface 172.)

Accordingly, during a scan cycle, the controller 190 can: serially drivethe columns of drives electrodes; serially read electrical values—(e.g.,voltages) representing electrical resistances across drive and senseelectrode pairs 105—from the rows of sense electrodes; detect a firstinput at a first location (e.g., an (x, y) location) on the touch sensorsurface 172 based on deviation of electrical values—read from a subsetof drive and sense electrode pairs 105 adjacent the first location—frombaseline resistance-based electrical values stored for this subset ofdrive and sense electrode pairs 105; and interpret a force magnitude ofthe first input based on a magnitude of this deviation. As describedbelow, the controller 190 can then drive an oscillating voltage acrossthe multi-layer inductor 150 in the substrate 102 during a hapticfeedback cycle in response to the force magnitude of the first inputexceeding a threshold input force.

The array of drive and sense electrode pairs 105 on the first and secondconductive layers of the substrate 102 and the force-sensitive layer 174can thus cooperate to form a resistive touch sensor readable by thecontroller 190 to detect lateral positions, longitudinal positions, andforce (or pressure) magnitudes of inputs (e.g., fingers, styluses,palms) on the touch sensor surface 172.

3.2 Capacitive Touch Sensor

In another implementation, the first and second conductive layers of thesubstrate 102 include columns of drive electrodes and rows of senseelectrodes (or vice versa) that terminate in a grid array of drive andsense electrode pairs 105 on the top conductive layer (or on both thetop and second conductive layers) of the substrate 102.

During a scan cycle, the controller 190 can: serially drive the columnsof drive electrodes; serially read electrical values (e.g., voltage,capacitance rise time, capacitance fall time, resonantfrequency)—representing capacitive coupling between drive and senseelectrode pairs 105—from the rows of sense electrodes; and detect afirst input at a first location (e.g., an (x, y) location) on the touchsensor surface 172 based on deviation of electrical values—read from asubset of drive and sense electrode pairs 105 adjacent the firstlocation—from baseline capacitance-based electrical values stored forthis subset of drive and sense electrode pairs 105. For example, thecontroller 190 can implement mutual capacitance techniques to readcapacitance values between these drive and sense electrode pairs 105 andto interpret inputs on the touch sensor surface 172 based on thesecapacitance values.

The array of drive and sense electrode pairs 105 on the first and secondconductive layers of the substrate 102 and the force-sensitive layer 174can thus cooperate to form a capacitive touch sensor readable by thecontroller 190 to detect lateral and longitudinal positions of inputs(e.g., fingers, styluses, palms) on the touch sensor surface 172.

3.3 Touchscreen

In one variation, the system includes (or interfaces with) a touchscreen196 arranged over the substrate and that includes: a digital display; atouch sensor arranged across the display; and a cover layer arrangedover the display and defining the touch sensor surface 172. Accordingly,in this variation, the controller is configured to drive the oscillatingvoltage across the multi-layer inductor during the haptic feedback cyclein response to the touchscreen 196 detecting the input on the touchsensor surface.

In particular, in this variation, the substrate 102 can: receive orintegrate with a touch screen (i.e., an integrated display and touchsensor); and can cooperate with the first magnetic element 181 and thecontroller 190 to vibrate the touch sensor surface over the touchscreen196 responsive to an input on the touch sensor surface, such as detectedby a separate controller coupled to the touchscreen 196.

4. Multi-Layer Inductor

As described above, the system 100 includes a multi-layer inductor 150formed by a set of interconnected spiral traces fabricated directlywithin conductive layers within the substrate 102.

Generally, the total inductance of a single spiral trace may be limitedby the thickness of the conductive layer. Therefore, the system 100 caninclude a stack of overlapping, interconnected spiral traces fabricatedon a set of adjacent layers of the substrate 102 to form a multi-layer,multi-turn, and/or multi-core inductor that exhibits greaterinductance—and therefore greater magnetic coupling to the set ofmagnetic elements—than a single spiral trace on a single conductivelayer of the substrate 102. These spiral traces can be coaxially alignedabout a common vertical axis (e.g., centered over the set of magneticelements) and electrically interconnected by a set of vias through theintervening substrate layers of the substrate 102.

Furthermore, the substrate 102 can include conductive layers ofdifferent thicknesses. Accordingly, spiral traces within thickerconductive layers of the substrate 102 can be fabricated with narrowertrace widths and more turns, and spiral traces within thinner conductivelayers of the substrate 102 can be fabricated with wider trace widthsand fewer turns in order to achieve similar electrical resistanceswithin each spiral trace over the same coil footprint. For example,lower conductive layers within the substrate 102 can include heavierlayers of conductive material (e.g., one-ounce copper approximately 35microns in thickness) in order to accommodate narrower trace widths andmore turns within the coil footprint in these conductive layers, therebyincreasing inductance of each spiral trace and yielding greater magneticcoupling between the multi-layer inductor 150 and the set of magneticelements during a haptic feedback cycle. Conversely, in this example,the upper layers of the substrate 102—which include many (e.g.,thousands of) drive and sense electrode pairs 105 of the touchsensor—can include thinner layers of conductive material.

4.1 Single Core+Even Quantity of Coil Layers

In one implementation shown in FIG. 2, the substrate 102 includes aneven quantity of spiral traces fabricated within an even quantity ofsubstrate layers within the substrate 102 to form a single-coilinductor.

In one example, the substrate 102 includes: a top layer 104 and anintermediate layer 106 containing the array of drive and sense electrodepairs 105; a first layer 110; a second layer 120; a third layer 130; anda fourth (e.g., a bottom) layer. In this example, the first layer 110includes a first spiral trace 111 coiled in a first direction anddefining a first end and a second end. In particular, the first spiraltrace 111 can define a first planar coil spiraling inwardly in aclockwise direction from the first end at the periphery of the firstplanar coil to the second end proximal a center of the first planarcoil. The second layer 120 includes a second spiral trace 122 coiled ina second direction opposite the first direction and defining a thirdend—electrically coupled to the second end of the first spiral trace111—and a fourth end. In particular, the second spiral trace 122 candefine a second planar coil spiraling outwardly in the clockwisedirection from the third end proximal the center of the second planarcoil to the fourth end at a periphery of the second planar coil.

Similarly, the third layer 130 includes a third spiral trace 133 coiledin the first direction and defining a fifth end—electrically coupled tothe fourth end of the second spiral trace 122—and a sixth end. Inparticular, the third spiral trace 133 can define a third planar coilspiraling inwardly in the clockwise direction from the fifth end at theperiphery of the third planar coil to the sixth end proximal a center ofthe third planar coil. Furthermore, the fourth layer includes a fourthspiral trace 144 coiled in the second direction and defining a seventhend—electrically coupled to the sixth end of the first spiral trace111—and an eighth end. In particular, the fourth spiral trace 144 candefine a fourth planar coil spiraling outwardly in the clockwisedirection from the seventh end proximal the center of the fourth planarcoil to the eighth end at a periphery of the fourth planar coil.

Accordingly: the second end of the first spiral trace 111 can be coupledto the third end of the second spiral trace 122 by a first via; thefourth end of the second spiral trace 122 can be coupled to the fifthend of the third spiral trace 133 by a second via; the sixth end of thethird spiral trace 133 can be coupled to the seventh end of the fourthspiral trace 144 by a third via; and the first, second, third, andfourth spiral traces 111, 122, 133, 144 can cooperate to form asingle-core, four-layer inductor. The controller 190 (or a driver): canbe electrically connected to the first end of the first spiral trace 111and the eighth end of the fourth spiral trace 144 (or “terminals” of themulti-layer inductor 150); and can drive these terminals of themulti-layer inductor 150 with an oscillating voltage during a hapticfeedback cycle in order to induce an alternating magnetic field throughthe multi-layer inductor 150, which couples to the magnetic elements andoscillates the substrate 102 within the chassis 192. In particular, whenthe controller 190 drives the multi-layer inductor 150 at a firstpolarity, current can flow in a continuous, clockwise direction throughthe first, second, third, and fourth spiral traces 111, 122, 133, 144 toinduce a magnetic field in a first direction around the multi-layerinductor 150. When the controller 190 reverses the polarity acrossterminals of the multi-layer inductor 150, current can reversedirections and flow in a continuous, counter-clockwise direction throughthe first, second, third, and fourth spiral traces in, 122, 133, 144 toinduce a magnetic field in a second, opposite direction at themulti-layer inductor 150.

Furthermore, in this implementation, because the multi-layer inductor150 spans an even quantity of conductive layers within the substrate102, the terminals of the multi-layer inductor 150 can be located on theperipheries of the first and last layers of the substrate 102 and thusenable direct connection to the controller 190 (or driver).

4.2 Single Core+Odd Quantity of Coil Layers

In another implementation shown in FIG. 1, the multi-layer inductor 150spans an odd number of (e.g., 3, 5) conductive layers of the substrate102. In this implementation, a conductive layer of the substrate 102 caninclude two parallel and offset spiral traces that cooperate with otherspiral traces in the multi-layer inductor 150 to locate the terminals ofthe multi-layer inductor 150 at the periphery of the multi-layerinductor 150 for direct connection to the controller 190 or driver.

In one example, the substrate 102 includes: a top layer 104 and anintermediate layer 106 containing the array of drive and sense electrodepairs 105; a first layer 110; a second layer 120; a third layer 130; anda fourth (e.g., a bottom) layer. In this example, the first layer 110includes a ground electrode (e.g., a continuous trace): spanning thefootprint of the array of drive and sense electrode pairs 105 in the topand intermediate layers 104, 106; driven to a reference potential by thecontroller 190; and configured to shield the drive and sense electrodepairs 105 from electrical noise generated by the multi-layer inductor150.

In this example, the third layer 130 includes a first spiral trace 111coiled in a first direction and defining a first end and a second end.In particular, the first spiral trace 111 can define a first planar coilspiraling inwardly in a clockwise direction from the first end at theperiphery of the first planar coil to the second end proximal a centerof the first planar coil. The second layer 120 includes a second spiraltrace 122 coiled in a second direction opposite the first direction anddefining a third end—electrically coupled to the second end of the firstspiral trace nil in the third layer 130—and a fourth end. In particular,the second spiral trace 122 can define a second planar coil spiralingoutwardly in the clockwise direction from the third end proximal thecenter of the second planar coil to the fourth end at a periphery of thesecond planar coil.

The third layer 130 further includes a third spiral trace 133 coiled inthe first direction and defining a fifth end—electrically coupled to thefourth end of the second spiral trace 122 in the second layer 120—and asixth end. In particular, the third spiral trace 133 can define a thirdplanar coil: spiraling inwardly in the clockwise direction from thefifth end at the periphery of the third planar coil to the sixth endproximal a center of the third planar coil; and nested within the firstplanar coil that also spirals inwardly in the clockwise direction withinthe third layer 130.

Furthermore, the fourth layer includes a fourth spiral trace 144 coiledin the second direction and defining a seventh end—electrically coupledto the sixth end of the first spiral trace 111—and an eighth end. Inparticular, the fourth spiral trace 144 can define a fourth planar coilspiraling outwardly in the clockwise direction from the seventh endproximal the center of the fourth planar coil to the eighth end at aperiphery of the fourth planar coil.

Accordingly: the second end of the first spiral trace 111 within thethird layer 130 can be coupled to the third end of the second spiraltrace 122 within the second layer 120 by a first via; the fourth end ofthe second spiral trace 122 within the second layer 120 can be coupledto the fifth end of the third spiral trace 133 within the third layer130 by a second via; the sixth end of the third spiral trace 133 withinthe third layer 130 can be coupled to the seventh end of the fourthspiral trace 144 within the fourth layer by a third via; and the first,second, third, and fourth spiral traces 111, 122, 133, 144 can cooperateto form a single-core, three-layer inductor. The controller 190: can beelectrically connected to the first end of the first spiral trace 111within the third layer 130 and the eight end of the fourth spiral trace144 within the fourth layer (or “terminals” of the multi-layer inductor150); and can drive these terminals of the multi-layer inductor 150 withan oscillating voltage during a haptic feedback cycle in order to inducean alternating magnetic field through the multi-layer inductor 150,which couples to the magnetic elements and oscillates the substrate 102within the chassis 192. In particular, when the controller 190 drivesthe multi-layer inductor 150 at a first polarity, current can flow in acontinuous, clockwise direction through the first, second, third, andfourth spiral traces 111, 122, 133, 144 within the second, third, andfourth layers of the substrate 102 to induce a magnetic field in a firstdirection around the multi-layer inductor 150. When the controller 190reverses the polarity across terminals of the multi-layer inductor 150,current can reverse directions and flow in a continuous,counter-clockwise direction through the first, second, third, and fourthspiral traces in, 122, 133, 144 to induce a magnetic field in a second,opposite direction at the multi-layer inductor 150.

Therefore, in this implementation, the substrate 102 can include an evennumber of single-coil layers and an odd number of two-coil layersselectively connected to form a multi-layer inductor 150 that includestwo terminals located on the periphery of the multi-layer inductor 150.

4.3 Double Core+Even Quantity of Coil Layers

In another implementation shown in FIGS. 3 and 7, the substrate 102includes an even quantity of spiral traces fabricated within an evenquantity of substrate layers within the substrate 102 to form adual-core inductor (that is, two separate single-core inductorsconnected in series).

In one example, the substrate 102 includes: a top layer 104 and anintermediate layer 106 containing the array of drive and sense electrodepairs 105; a first layer no; a second layer 120; a third layer 130; anda fourth (e.g., a bottom) layer.

In this example, the first layer 110 includes a first spiral trace 111coiled in a first direction and defining a first end and a second end.In particular, the first spiral trace nil can define a first planar coilspiraling inwardly in a clockwise direction from the first end at theperiphery of the first planar coil to the second end proximal a centerof the first planar coil. The second layer 120 includes a second spiraltrace 122 coiled in a second direction opposite the first direction anddefining a third end—electrically coupled to the second end of the firstspiral trace 111—and a fourth end. In particular, the second spiraltrace 122 can define a second planar coil spiraling outwardly in theclockwise direction from the third end proximal the center of the secondplanar coil to the fourth end at a periphery of the second planar coil.The third layer 130 includes a third spiral trace 133 coiled in thefirst direction and defining a fifth end—electrically coupled to thefourth end of the second spiral trace 122—and a sixth end. Inparticular, the third spiral trace 133 can define a third planar coilspiraling inwardly in the clockwise direction from the fifth end at theperiphery of the third planar coil to the sixth end proximal a center ofthe third planar coil. Furthermore, the fourth layer includes a fourthspiral trace 144 coiled in the second direction and defining a seventhend—electrically coupled to the sixth end of the first spiral trace111—and an eighth end. In particular, the fourth spiral trace 144 candefine a fourth planar coil spiraling outwardly in the clockwisedirection from the seventh end proximal the center of the fourth planarcoil to the eighth end at a periphery of the fourth planar coil.

Accordingly: the second end of the first spiral trace 111 can be coupledto the third end of the second spiral trace 122 by a first via; thefourth end of the second spiral trace 122 can be coupled to the fifthend of the third spiral trace 133 by a second via; the sixth end of thethird spiral trace 133 can be coupled to the seventh end of the fourthspiral trace 144 by a third via; and the first, second, third, andfourth spiral traces 111, 122, 133, 144 can cooperate to form a firstsingle-core, four-layer inductor.

Furthermore, in this example, the first layer 110 includes a fifthspiral trace adjacent the first spiral trace 111, coiled in the seconddirection, and defining a ninth end—coupled to the first end of thefirst planar coil—and a tenth end. In particular, the fifth spiral tracecan define a fifth planar coil spiraling inwardly in a clockwisedirection from the ninth end at the periphery of the fifth planar coilto the tenth end proximal a center of the fifth planar coil. The secondlayer 120 includes a sixth spiral trace adjacent the second spiral trace122, coiled in the first direction, and defining an eleventhend—electrically coupled to the tenth end of the fifth spiral trace—anda twelfth end. In particular, the sixth spiral trace can define a sixthplanar coil spiraling outwardly in the clockwise direction from theeleventh end proximal the center of the sixth planar coil to the twelfthend at a periphery of the sixth planar coil. The third layer 130includes a seventh spiral trace adjacent the third spiral trace 133,coiled in the second direction, and defining a thirteenthend—electrically coupled to the twelfth end of the sixth spiraltrace—and a fourteenth end. In particular, the seventh spiral trace candefine a seventh planar coil spiraling inwardly in the clockwisedirection from the thirteenth end at the periphery of the seventh planarcoil to the fourteenth end proximal a center of the seventh planar coil.Furthermore, the fourth layer includes an eighth spiral trace adjacentthe fourth spiral trace 144, coiled in the first direction, and defininga fifteenth end—electrically coupled to the fourteenth end of theseventh spiral trace—and a sixteenth end. In particular, the eighthspiral trace can define an eighth planar coil spiraling outwardly in theclockwise direction from the fifteenth end proximal the center of theeighth planar coil to the sixteenth end at a periphery of the eighthplanar coil.

Accordingly: the tenth end of the fifth spiral trace can be coupled tothe eleventh end of the sixth spiral trace by a fourth via; the twelfthend of the sixth spiral trace can be coupled to the thirteenth end ofthe seventh spiral trace by a fifth via; the fourteenth end of theseventh spiral trace can be coupled to the fifteenth end of the eighthspiral trace by a sixth via; and the fifth, sixth, seventh, and eighthspiral traces can cooperate to form a second single-core, four-layerinductor.

Furthermore, the first end of the first spiral trace 111 can be coupledto (e.g., form a continuous trace with) the ninth end of the fifthspiral trace within the first conductive layer. The first and secondsingle-core, four-layer inductors can therefore be fabricated in seriesto form a four-layer, dual-core inductor with the eighth and sixteenthends of the fourth and eighth spiral traces, respectively, forming theterminals of the four-layer, dual-core inductor. Therefore, when thesefirst and second multi-layer inductors are driven to a first polarity,current can flow in a continuous circular direction through both thefirst multi-layer inductor such that the first and second multi-layerinductors produce magnetic fields in the same phase and in the samedirection.

The controller 190 (or a driver): can be electrically connected to theseterminals and can drive these terminals with an oscillating voltageduring a haptic feedback cycle in order to induce: a first alternatingmagnetic field through the first single-core, four-layer inductor(formed by the first, second, third, and fourth spiral traces 111, 122,133, 144); and a second alternating magnetic field—in phase with thefirst alternating magnetic field—through the second single-core,four-layer inductor (formed by the fifth, sixth, seventh, and eighthspiral traces). In particular, when the controller 190 drives thefour-layer, dual-core inductor at a first polarity, current can flow: ina continuous, clockwise direction through the first, second, third, andfourth spiral traces 111, 122, 133, 144 to induce a magnetic field in afirst direction around the first single-core, four-layer inductor; andin a continuous, clockwise direction through the fifth, sixth, seventh,and eighth spiral traces to induce a magnetic field in the firstdirection around the second single-core, four-layer inductor. When thecontroller 190 reverses the polarity across terminals of the dual-core,four-layer inductor, current can reverse directions to: flow in acontinuous, counter-clockwise direction through the first, second,third, and fourth spiral traces 111, 122, 133, 144 to induce a magneticfield in a second, opposite direction around the first single-core,four-layer inductor; and in a continuous, counter-clockwise directionthrough the fifth, sixth, seventh, and eighth spiral traces to induce amagnetic field in the second direction around the second single-core,four-layer inductor.

4.4 Double Core+Odd Quantity of Coil Layers

In a similar implementation, the substrate 102 includes an odd quantityof spiral traces fabricated within an odd quantity of substrate layerswithin the substrate 102 to form a dual-core inductor.

For example, in this implementation, the dual-core inductor can includetwo single-coil, three-layer inductors connected in series. In thisexample, each single-coil, three-layer inductors includes: an evennumber of single-coil layers; and an odd number of two-coil layersselectively connected to form a single-coil, three-layer inductor thatincludes two terminals located on the periphery of the single-coil,three-layer inductor, as described above.

5. Magnetic Element

Generally, the system 100 includes a set of magnetic elements: rigidlycoupled to the chassis 192 beneath the multi-layer inductor 150; andconfigured to magnetically couple to the multi-layer inductor 150 duringa haptic feedback cycle, thereby applying an oscillating force to themulti-layer inductor 150 and oscillating the substrate 102—and thereforethe touch sensor surface 172—within the receptacle 194 during thishaptic feedback cycle.

In particular, the spiral traces within the multi-layer inductor 150 canspan a coil footprint, such as a rectangular or ellipsoidal footprintincluding: long sides parallel to a primary axis of the multi-layerinductor 150; and short sides parallel to a secondary axis of themulti-layer inductor 150. For example: the substrate 102 can be 5 inchesin width and 3 inches in length; the touch sensor surface 172 can spanan area approximately 5 inches by 3 inches over the substrate 102; andthe coil footprint of each single-core multi-layer inductor 150 withinthe substrate 102 can be approximately 1.5 inches in length and 0.5inches in width with the primary axis of the single-core multi-layerinductor 150 extending laterally across the width of the substrate 102.

5.1 Horizontal Oscillation: Single-Core Multi-Layer Inductor

In one implementation, the set of magnetic elements are arrangedrelative to the multi-layer inductor 150 in order to induce anoscillating force—between the multi-layer inductor 150 and the magneticelements—parallel to the touch sensor surface 172 such that thesubstrate 102 oscillates horizontally in a plane parallel to the touchsensor surface 172 during a haptic feedback cycle, as shown in FIGS. 2and 4A.

In this implementation, the system 100 can include a first magneticelement 181: arranged in a receptacle 194 defined by the chassis 192 ofthe device; defining a first magnetic polarity facing the multi-layerinductor 150; and extending along a first side of the primary axis. Inthis implementation, the system 100 can similarly include a secondmagnetic element 182: arranged in the receptacle 194; defining a secondmagnetic polarity facing the multi-layer inductor 150; and extendingalong a second side of the primary axis adjacent the first magneticelement 181. In particular, the first magnetic element 181 can bearranged immediately adjacent and the second magnetic element. The firstand second magnetic elements 181, 182 can be arranged directly under themulti-layer inductor 150 and can face the multi-layer inductor 150 withopposing polarities, as shown in FIG. 4A. When the controller 190 drivesthe multi-layer inductor 150 with an alternating voltage (or current),the multi-layer inductor 150 can generate a magnetic field that extendsvertically through the substrate 102 (e.g., normal to the touch sensorsurface 172) and interacts with the opposing magnetic fields of thefirst and second magnetic elements 181, 182. More specifically, when thecontroller 190 drives the multi-layer inductor 150 to a positive voltageduring a haptic feedback cycle, the multi-layer inductor 150 cangenerate a magnetic field that extends vertically through the substrate102 in a first vertical direction, which: attracts the first magneticelement 181 (arranged with the first polarity facing the multi-layerinductor 150); repels the second magnetic element 182 (arranged with thesecond polarity facing the multi-layer inductor 150); yields a firstlateral force a first lateral direction; and shifts the substrate 102laterally in the first lateral direction. When the controller 190 thenreverses the voltage across the multi-layer inductor 150 during thishaptic feedback cycle, the multi-layer inductor 150 can generate amagnetic field that extends vertically through the substrate 102 in theopposing vertical direction, which: repels the first magnetic element181; attracts the second magnetic element 182; yields a second lateralforce an second, opposite lateral direction; and shifts the substrate102 laterally in the second lateral direction.

Therefore, by oscillating the polarity of the multi-layer inductor 150,the controller 190 can: induce oscillating interactions (i.e.,alternating attractive and repelling forces)—parallel to the touchsensor surface 172—between the multi-layer inductor 150 and the magneticelements; and thus oscillate the substrate 102 and touch sensor surface172 horizontally (e.g., within a plane parallel to the touch sensorsurface 172).

Therefore, in this implementation, the spiral traces of the single-coremulti-layer inductor 150 can define: a first length (e.g., 1.5 inches)along the primary axis of the multi-layer inductor 150; and a firstwidth (e.g., 0.5 inch)—less than first length—along the secondary axisof the multi-layer inductor 150. Furthermore, the first magnetic element181 can define: a length parallel to and offset from the primary axisand approximating the first length of the spiral traces; and a secondwidth parallel to the secondary axis of the multi-layer inductor 150 andapproximately half of the first width of the spiral traces. The secondmagnetic element 182 can similarly define: a length parallel to andoffset from the primary axis and approximating the first length of thespiral traces; and a width parallel to the secondary axis of themulti-layer inductor 150 and approximately half of the first width ofthe spiral traces. The first and second magnetic elements 181, 182 canbe abutted and arranged on each side of the primary axis of themulti-layer inductor 150.

For example, the set of magnetic elements can include a permanent dipolemagnet arranged in the receptacle 194 of the device and centered underthe multi-layer inductor 150 such that the two poles of the set ofmagnetic elements are located on opposite sides of the primary axis ofthe multi-layer inductor 150. As described above, the set of magneticelements can also include a set of permanent dipole magnets arranged inan antipolar configuration (e.g., a Halbach array).

The controller 190 (or the driver) can therefore polarize themulti-layer inductor 150 by applying an alternating voltage across thefirst and second terminals of the multi-layer inductor 150, therebyinducing an alternating current through the set of spiral traces,inducing an alternating magnetic field normal to the touch sensorsurface, inducing oscillating magnetic coupling between the multi-layerinductor 150 and the set of magnetic elements, and thus vibrating thesubstrate 102 in a plane parallel to the touch sensor surface 172 duringa haptic feedback cycle.

5.2 Horizontal Oscillation: Dual-Core Multi-Layer Inductor

Similarly, in the implementation described above in which the substrate102 includes two adjacent single-core, multi-layer inductors 150connected in series, the system 100 can include: a first magneticelement 181 arranged in the receptacle 194, defining a first magneticpolarity facing the first single-core multi-layer inductor 150, andextending along a first side of a first primary axis of the firstsingle-core multi-layer inductor 150; a second magnetic element 182arranged in the receptacle 194, defining a second magnetic polarityfacing the first single-core multi-layer inductor 150, and extendingalong a second side of the first primary axis adjacent the firstmagnetic element 181; a third magnetic element arranged in thereceptacle 194, defining the second magnetic polarity facing the secondsingle-core multi-layer inductor 150, and extending along a first sideof a second primary axis of the second single-core multi-layer inductor150; and a fourth magnetic element arranged in the receptacle 194,defining the first magnetic polarity facing the second single-coremulti-layer inductor 150, and extending along a second side of thesecond primary axis adjacent the third magnetic element, as shown inFIG. 6.

Accordingly, by oscillating the polarity of the first and secondsingle-core multi-layer inductors 150—which include traces that spiralin the same direction and are therefore in phase—the controller 190 can:induce oscillating interactions parallel to the touch sensor surface 172between the first single-core multi-layer inductor 150, the firstmagnetic element 181, and the second magnetic element 182 and betweenthe second single-core multi-layer inductor 150, the third magneticelement, and the fourth magnetic element; and thus oscillate thesubstrate 102 and touch sensor surface 172 horizontally (e.g., within aplane parallel to the touch sensor surface 172).

5.3 Vertical Oscillation

In another implementation, the set of magnetic elements are arrangedrelative to the multi-layer inductor 150 in order to induce anoscillating force—between the multi-layer inductor 150 and the magneticelements—normal to the touch sensor surface 172 such that the substrate102 oscillates vertically within the chassis 192 during a hapticfeedback cycle, as shown in FIGS. 1 and 4B.

In the implementation described above in which the substrate 102includes a single-core multi-layer inductor 150, the system 100 caninclude a first magnetic element 181: arranged in the receptacle 194 ofthe chassis 192; defining a first magnetic polarity facing thesingle-core multi-layer inductor 150; approximately centered under themulti-layer inductor 150; and extending laterally across the primaryaxis of the multi-layer inductor 150. The first magnetic element 181 canthus generate a magnetic field that extends predominantly verticallytoward the multi-layer inductor 150 and that is approximately centeredunder the multi-layer inductor 150. More specifically, the firstmagnetic element 181 can generate a magnetic field that extendspredominately normal to the touch sensor surface 172 proximal the centerof the multi-layer inductor 150. As shown in FIG. 4B, when thecontroller 190 drives the multi-layer inductor 150 to a positive voltageduring a haptic feedback cycle, the multi-layer inductor 150 cangenerate a magnetic field that extends vertically through the substrate102 in a first vertical direction, which: repels the first magneticelement 181 (arranged with the first polarity facing the multi-layerinductor 150); yields a first vertical force in a first verticaldirection; and lifts the substrate 102 vertically off of the firstmagnetic element 181. When the controller 190 then reverses the voltageacross the multi-layer inductor 150 during this haptic feedback cycle,the multi-layer inductor 150 can generate a magnetic field that extendsvertically through the substrate 102 in a second, opposite verticaldirection, which: attracts the first magnetic element 181; yields asecond vertical force in a second, opposite vertical direction; anddraws the substrate 102 downward and back toward the first magneticelement 181.

Therefore, by oscillating the polarity of the multi-layer inductor 150,the controller 190 can: induce oscillating interactions (i.e.,alternating attractive and repelling forces)—normal to the touch sensorsurface 172—between the multi-layer inductor 150 and the first magneticelement 181; and thus oscillate the substrate 102 and touch sensorsurface 172 vertically (e.g., normal to the touch sensor surface 172).

Furthermore, the system 100 can be reconfigured for vertical andhorizontal oscillations of the touch sensor surface 172 by exchanging: asingle magnetic element that spans the full width of and is centeredunder the multi-layer inductor 150; for a pair of opposing magneticelements arranged under the multi-layer inductor 150 and on each of theprimary axis of the multi-layer inductor 150 with no or minimal othermodifications to the system 100, as shown in FIG. 6.

5.4 Vertical Oscillation: Dual-Core Multi-Layer Inductor

Similarly, in the implementation described above in which the substrate102 includes two adjacent single-core, multi-layer inductors 150connected in series and in phase (i.e., phased by 0°), the system 100can include a first magnetic element 181: arranged in the receptacle194; defining a first magnetic polarity facing the first single-coremulti-layer inductor 150; approximately centered under the firstsingle-core multi-layer inductor 150; and extending laterally across theprimary axis of the first single-core multi-layer inductor 150. Thesystem 100 can similarly include a second magnetic element 182: arrangedin the receptacle 194 adjacent the first magnetic element 181; definingthe first magnetic polarity facing the second single-core multi-layerinductor 150; approximately centered under the second single-coremulti-layer inductor 150; and extending laterally across the primaryaxis of the second single-core multi-layer inductor 150, as shown inFIGS. 3 and 4B.

Accordingly, by oscillating the polarity of the first and secondsingle-core multi-layer inductors 150—which are in phase—the controller190 can: induce oscillating interactions normal to the touch sensorsurface 172 between the first single-core multi-layer inductor 150 andthe first magnetic element 181 and between the second single-coremulti-layer inductor 150 and the second magnetic element 182; and thusoscillate the substrate 102 and touch sensor surface 172 vertically(e.g., normal to the touch sensor surface 172).

6. Chassis Integration

As described above, the substrate 102 is flexibly mounted to the chassis192 (e.g., within or over a receptacle 194 defined by the chassis 192)to enable the substrate 102 to oscillate horizontally or verticallyrelative to the chassis 192 during a haptic feedback cycle.

6.1 Deflection Spacers

In one configuration shown in FIGS. 2, 8, and 10A and as described inU.S. patent application Ser. No. 17/191,631, which is incorporated inits entirety by this reference: the top layer 104 of the substrate 102includes an array of drive and sense electrode pairs 105 arranged in agrid array, at a first density, and in a mutual capacitanceconfiguration; and a bottom layer 140 of the substrate 102 includes asecond set of sensor traces 146 (e.g., a sparse perimeter array ofinterdigitated drive and sense electrode pairs 105) located proximal aperimeter of the substrate 102 at a second density less than the firstdensity. In this implementation, the system 100 further includes a setof deflection spacers 160 (e.g., short elastic columns or buttons,adhesive films) coupled to the bottom layer 140 of the substrate 102over each sensor trace and configured to support the substrate 102 onthe chassis 192 of the device. In particular, each deflection spacer 160can include a force-sensitive layer 174: arranged across a sensor tracein the second set of sensor traces 146; and exhibiting changes incontact resistance across the sensor trace responsive to a load on thetouch sensor surface 172 that compresses the deflection space againstthe substrate 102.

Accordingly, in this implementation, the controller 190 can: read afirst set of electrical values—representing capacitive coupling betweendrive and sense electrode pairs 105—from the set of drive and senseelectrode pairs 105; and detect a first input at a first location on thetouch sensor surface 172 based on deviation of electrical values—readfrom a subset of drive and sense electrode pairs 105 adjacent the firstlocation—from baseline capacitance values stored for this subset ofdrive and sense electrode pairs 105. During this same scan cycle, thecontroller 190 can also: read a second set of electrical values (e.g.,electrical resistances)—representing compression of the set ofdeflection spacers 160 against the second set of sensor traces 146—fromthe second set of sensor traces 146; interpret a force magnitude of thefirst input based on magnitudes of deviations of electrical (e.g.,resistance) values from baseline electrical values across the set ofsensor traces 146; and drive an oscillating voltage across themulti-layer inductor 150 during a haptic feedback cycle in response tothe force magnitude of the first input exceeding a threshold inputforce.

Generally, in this configuration, the set of deflection spacers 160: areinterposed between the bottom layer 140 of the substrate 102 and thebase of the receptacle 194; and vertically support the substrate 102within the receptacle 194.

In one implementation, each deflection spacer 160 includes a coupon:bonded to the bottom face of the substrate 102 and to the base of thereceptacle 194; and formed in a low-durometer or elastic material thatdeflects laterally (or “shears”) to enable the substrate 102 totranslate laterally within the receptacle 194 responsive to alternatingmagnetic coupling between the multi-layer inductor 150 and the set ofmagnetic elements during a haptic feedback cycle. In anotherimplementation, each deflection spacer 160 includes: a coupon bonded tothe bottom face of the substrate 102; and a bottom face coated orincluding a low-friction material configured to slide across the base ofthe receptacle 194 to enable the substrate 102 to translate laterally inthe receptacle 194 during a haptic feedback cycle while also verticallysupporting the substrate 102 over the receptacle 194. In yet anotherimplementation and as described below, each deflection spacer 160 ismounted to a spring or flexure element—which is mounted to the chassis192—that enables the deflection spacer 160 to move laterally within thereceptacle 194 while vertically supporting the substrate 102 within thereceptacle 194.

In this configuration, the bottom conductive layer of the substrate 102can include a pair of interdigitated drive and sense electrodes in eachdeflection spacer location about the perimeter of the substrate 102, asshown in FIG. 2. Furthermore, each deflection spacer 160 can include alayer of force-sensitive material—such as described above—facing thepair of interdigitated drive and sense electrodes at this deflectionspacer location on the substrate 102. The controller 190 can thus: readan electrical resistance (or a voltage representing electricalresistance) across a pair of sensor traces 146 at a deflection spacerlocation; and transform this resistance into a force magnitude carriedfrom the touch sensor surface 172, into the substrate 102, and into theadjacent the deflection spacer 160. In particular, the system 100 caninclude multiple deflection spacers 160, and the controller 190 can:read electrical values from sensor traces 146 at each deflection spacerlocation; convert these electrical values into force magnitudes carriedby each deflection spacer 160; and aggregate these force magnitudes intoa total force magnitude of an input on the touch sensor surface 172.

Therefore, in this configuration, the substrate 102 can define a unitarystructure including a dense array of drive and sense electrode pairs 105that form a touch sensor, a column of spiral traces that form amulti-layer inductor 150, and a sparse array of drive and senseelectrode pairs 105 that form a set of force sensors that support thesubstrate 102 on the chassis 192.

6.1.1 Capacitive Deflection Spacer

Alternatively, the bottom layer 140 of the substrate 102 can include asparse array of sensor traces 146 (e.g., interdigitated drive and senseelectrode pairs 105) arranged in a capacitive sensing configuration ateach deflection spacer location such that each of these sensor traces146 capacitively couples: to the chassis 192; to the adjacent deflectionspacer 160; to a spring element 162 supporting the substrate 102 at thisdeflection spacer location; or to another fixed metallic element at thisdeflection spacer location. Accordingly, during a scan cycle, thecontroller 190 can: read capacitance values from the sensor traces 146at these deflection spacer locations; convert these capacitance valuesinto force magnitudes carried by each deflection spacer 160 during thescan cycle; and aggregate these force magnitudes into a total forcemagnitude of an input on the touch sensor surface 172.

6.1.2 Inductor Integration with Deflection Spacers

Furthermore, in this configuration, the multi-layer inductor 150 can beintegrated into a region of the substrate 102 offset from the deflectionspacer 160 locations (i.e., inset from regions of the substrate 102occupied by sensor traces 146 in these deflection spacer locations). Forexample, the array of deflection spacers 160 can be located proximal aperimeter of the substrate 102, and the spiral traces that form themulti-layer inductor 150 can be arranged near a lateral and longitudinalcenter of the substrate 102 in order to limit injection of electricalnoise from the multi-layer inductor 150 into sensor traces 146 in thesedeflection spacers 160 during a haptic feedback cycle, as shown in FIG.2.

6.2 Spring-Loaded Chassis Interface

Additionally or alternatively as shown in FIGS. 2, 3, and 22 and asdescribed in U.S. patent application Ser. No. 17/191,631, the system 100can include a chassis interface 166: configured to mount to the chassis192 of the device; and defining a set of spring elements 162 coupled tothe substrate 102 (e.g., via a set of deflection spacers 160) andconfigured to deflect out of the plane of the chassis interface 166responsive to an input on the touch sensor surface 172 and/or responsiveto actuation of the multi-layer inductor 150 during a haptic feedbackcycle.

In this implementation, the chassis 192 of the computing device caninclude a chassis receptacle 194 defining a depth approximating (orslightly more than) the thickness of a set of deflection spacers 160(e.g., 1.2-millimeter chassis receptacle 194 depth for1.0-millimeter-thick deflection spacers 160). The deflection spacers 160are bonded to the chassis interface 166 at each spring element 162. Thechassis interface 166 can then be rigidly mounted to the chassis 192over the receptacle 194, such as via a set of threaded fasteners or anadhesive. The substrate 102 and the set of deflection spacers 160 maythus transfer a force—applied to the touch sensor surface 172—into thesespring elements 162, which deflect inwardly below a plane of the chassisinterface 166 and into the chassis receptacle 194.

(In the configuration described above in which the substrate 102includes sensors traces at these deflection spacer locations, eachspacer is also compressed between the substrate 102 and the adjacentspring element 162 when a force is applied to the touch sensor surface172 and therefore exhibits a change in its local contact resistanceacross the adjacent sensor trace proportional to the force carried intothe adjacent spring element 162. The controller 190 can therefore readelectrical values (e.g., a resistances) across these sensor traces 146and convert these electrical values into portion of the input forcecarried by each sensor trace.)

In one implementation, the chassis interface 166 and spring elements 162define a unitary structure. In one example, the chassis interface 166includes a thin-walled structure (e.g., a stainless steel 20-gage, or0.8-millimeter-thick sheet) that is punched, etched, or laser-cut toform a flexure aligned to each deflection spacer location. Thus, in thisexample, each spring element 162 can define a flexure—such as amulti-arm spiral flexure—configured to laterally and longitudinallylocate the system 100 over the chassis 192 and configured to deflectinwardly and outwardly from a nominal plane defined by the thin-walledstructure. More specifically, in this example, the chassis interface 166can include a unitary metallic sheet structure arranged between thesubstrate 102 and the chassis 192 and defining a nominal plane. Eachspring element 162: can be formed (e.g., fabricated) in the unitarymetallic structure; can define a stage coupled to a spacer opposite thebottom layer 140 of the substrate 102; can include a flexure fabricatedin the unitary metallic structure; and can be configured to return toapproximately the nominal plane in response to absence of a touch inputapplied to the touch sensor surface 172.

Furthermore, in this implementation, the magnetic elements can bearranged in the receptacle 194, and the spring elements 162 can locatethe bottom layer 140 of the substrate 102 at a nominal gap (e.g., onemillimeter) above the magnetic elements. However, application of aninput on the touch sensor surface 172 can compress the spring elements162, thereby closing this gap and bringing the multi-layer inductor 150closer to the magnetic element, which may increase magnetic couplingbetween the multi-layer inductor 150 and the magnetic elements,increasing a peak-to-peak force between the multi-layer inductor 150 andthe magnetic elements, and increasing the oscillation amplitude of thesubstrate 102 during a haptic feedback cycle, as shown in FIG. 22.Therefore, the spring elements 162 can compress during application of aninput on the touch sensor surface 172, thereby a) closing a gap betweenthe multi-layer inductor 150 and the magnetic elements and b) increasingthe oscillation amplitude of the substrate 102 during a haptic feedbackcycle—responsive to this input—proportional to the force magnitude ofthis input.

Accordingly, a low-force input on the touch sensor surface 172 mayminimally compress the springs elements, minimally reduce the gapbetween the multi-layer inductor 150 and the magnetic elements, and thusyield low-amplitude oscillations during a haptic feedback cycleresponsive to this low-force input. Conversely, a high-force input onthe touch sensor surface 172 may compress the spring elements by alarger distance, significantly reduce the gap between the multi-layerinductor 150 and the magnetic elements, and thus yield higher-amplitudeoscillations during a haptic feedback cycle responsive to thishigh-force input.

Therefore, in this configuration, the system 100 can include a set ofspring elements 162: supporting the substrate 102 within the receptacle194 with the multi-layer inductor 150 located over the first magneticelement 181 and the second magnetic element 182; and biasing thesubstrate 102 within the receptacle 194 to locate the multi-layerinductor 150 at a nominal offset distance above the first magneticelement 181 and the second magnetic element 182. In particular, thespring elements 162 can compress responsive to application of an inputon the touch sensor surface 172 to: locate the multi-layer inductor 150at a second offset distance, less than the nominal offset distance,above the first magnetic element 181 and the second magnetic element182; and increase magnetic coupling between the multi-layer inductor150, the first magnetic element 181, and the second magnetic element 182during the haptic feedback cycle.

For example, the set of spring elements 162 can bias the substrate 102within the receptacle 194 to locate the multi-layer inductor 150 (or thebottom spiral trace of the multi-layer inductor 150 in the bottom layer140 of the substrate 102) at a nominal offset distance—between 400 and600 microns—above the magnetic elements. The spring elements 162 canalso cooperate to yield a spring constant between 800 and 1200 grams permillimeter across the touch sensor surface 172. Therefore, applicationof force greater than approximately 500 grams to the touch sensorsurface 172 can fully compress the set of spring elements 162. However,the system 100 can also exhibit increasing oscillation amplitudes of thesubstrate 102 during haptic feedback cycles as a function of magnitudeof applied force on the touch sensor surface 172, such as from a minimumthreshold force of 5 grams up to the maximum force of 500 grams.

(In similar implementations shown in FIGS. 11A, 11B, 11C, and 11D, thesubstrate 102 can be mounted to the chassis 192 via a set of flexiblegrommets that are compliant in vertical and/or horizontal directions toenable the substrate 102 to oscillation within the receptacle 194 duringa haptic feedback cycle.)

6.3 Spring Elements and Chassis Interface

In a similar variations shown in FIGS. 20 and 21, the system includes aset of deflection spacers 160, wherein each deflection spacer in the setis arranged over a discrete deflection spacer location—in a set ofdiscrete deflection spacer locations—on a bottom surface (e.g., thebottom layer) of the substrate below. The system can further include anarray of spring elements 162: that couple the set of deflection spacers160 to the chassis of the computing device; supporting the substrate onthe chassis; and configured to yield to oscillation of the substrate(e.g., vertically or horizontally) responsive to an oscillating voltagedriven across the multi-layer inductor by the controller 190 during ahaptic feedback cycle.

In one implementation shown in FIG. 20, the system includes chassisinterface 166 defining a unitary metallic structure: arranged betweenthe substrate and the chassis; that defines an aperture below themulti-layer inductor; and that comprises a set of flexures arrange aboutthe aperture and defining the array of spring elements 162 (e.g.,flexures). In this implementation, the system can also include amagnetic yoke 184 arranged in the aperture of the unitary metallicstructure; and the first magnetic element and the second magneticelement can be arranged on the magnetic yoke below the multi-layerinductor. Accordingly, the magnetic yoke 184 can limit a permeabilitypath for magnetic field lines between the rear faces of the first andsecond magnetic elements opposite the substrate.

6.3.1 Chassis Interface

More specifically, in this variation, the system 100 can include anarray of spring elements 162: coupled to the set of deflection spacers160 at the array of support locations; configured to support thesubstrate 102 on a chassis of a computing device; and configured toyield to displacement of the substrate 102 downward toward the chassisresponsive to forces applied to the touch sensor surface 172.

In one implementation, the system 100 includes a chassis interface 166:configured to mount to the chassis of a computer system; and defining aset of spring elements 162 supported by each spacer 160 and configuredto deflect out of the plane of the chassis interface 166 responsive toan input on the touch sensor surface 172.

In this implementation, the chassis of the computing device can includea chassis receptacle defining a depth approximating (or slightly morethan) the thickness of the deflection spacers 160 (e.g., 1.2-millimeterdepth for 1.0-millimeter-thick spacers 160). The deflection spacers 160are bonded to the chassis interface 166 at each spring element 162. Thechassis interface 166 can then be rigidly mounted to the chassis overthe receptacle, such as via a set of threaded fasteners or an adhesive.The substrate 102 and the set of deflection spacers 160 may thustransfer a force—applied to the touch sensor surface 172—into thesespring elements 162, which deflect inwardly below a plane of the chassisinterface 166 and into the chassis receptacle. Concurrently, each spacer160 is compressed between the substrate 102 and the adjacent springelement 162 and therefore exhibits a change in its local bulk resistanceproportional to the force carried by this adjacent spring element 162.

6.3.2 Unitary Spring Elements and Chassis Interface Structure

In one implementation, the chassis interface 166 and spring elements 162define a unitary structure (e.g., a “spring plate”). In one example, thechassis interface 166 includes a thin-walled structure (e.g., astainless steel 20-gage, or 0.8-millimeter-thick sheet) that is punched,etched, or laser-cut to form a flexure aligned to each support location.Thus, in this example, each spring element 162 can define a flexure—suchas a multi-arm spiral flexure—configured to laterally and longitudinallylocate the system 100 over the chassis and configured to deflectinwardly and outwardly from a nominal plane defined by the thin-walledstructure.

More specifically, in this example, the chassis interface 166 caninclude a unitary metallic sheet structure arranged between thesubstrate 102 and the chassis and defining a nominal plane. Each springelement 162: can be formed (e.g., fabricated) in the unitary metallicstructure; can include a flexure fabricated in the unitary metallicstructure; and can be configured to return to approximately the nominalplane in response to absence of a touch input applied to the touchsensor surface 172.

6.3.3 Spring Element Locations

In one implementation, the substrate 102 defines a rectangular geometrywith support locations proximal the perimeter of this rectangulargeometry. Accordingly, the deflection spacers 160 and the array ofspring elements 162 can cooperate to support the perimeter of thesubstrate 102 against the chassis of the computing device.

In this implementation, the substrate 102 and the cover layer cancooperate to form a semi-rigid structure that resists deflection betweensupport locations. For example, with the perimeter of the substrate 102supported by the array of spring elements 162, the substrate 102 and thecover layer can exhibit less than 0.3 millimeter of deflection out of anominal plane when a force of ˜1.6 Newtons (i.e., 165 grams, equal to an“click” input force threshold) is applied to the center of the touchsensor surface 172. The substrate 102 and the cover layer can thereforecooperate to communicate this applied force to the perimeter of thesubstrate 102 and thus into the deflection spacers 160 and springelements 162 below.

In this implementation, inclusion of a spring element 162 supporting thecenter of the substrate 102 may produce: a relatively high ratio ofapplied force to vertical displacement of the substrate 102 near boththe center and the perimeter of the substrate 102; and a relatively lowratio of applied force to vertical displacement of the substrate 102 inan intermediate region around the center and inset from the perimeter ofthe substrate 102. Therefore, to avoid such non-linear changes in ratioof applied force to vertical displacement of the substrate 102—which maycause confusion or discomfort for a user interfacing with the system100—the system 100 can: include spring elements 162 that support theperimeter of the substrate 102; exclude spring elements 162 supportingthe substrate 102 proximal its center; and include a substrate 102 and acover layer that form a substantially rigid structure.

More specifically, the array of spring elements 162 can support theperimeter of the substrate 102, and the substrate 102 and the coverlayer can form a substantially rigid structure in order to achieve aratio of applied force to vertical displacement of the substrate 102that is approximately consistent or that changes linearly across thetotal area of the touch sensor surface 172.

6.3.4 Resistive Force Sensor

In this variation and as described above, the substrate can include abottom layer: arranged below the second layer opposite the first layer;and comprising a set of sensor traces arranged at the set of discretedeflection spacer locations. Each deflection spacer in the set ofdeflection spacers 160 can include a force-sensitive material exhibitingvariations in local contact resistance responsive to variations inapplied force.

More specifically, in this variation, the array of spring elements 162can include a unitary metallic structure arranged between the substrateand the chassis and defining a nominal plane. Each spring element: canbe formed in the unitary metallic structure; can define a stage coupledto a deflection spacer, in the set of deflection spacers 160, oppositethe bottom layer of the substrate; and can be configured to returntoward the nominal plane in response to absence of inputs applied to thetouch sensor surface. Each deflection spacer can electrically couple anadjacent sensor trace—in the set of sensor traces on the bottom layer ofthe substrate—with a resistance that varies according to magnitude offorces applied to the touch sensor surface and carried into thedeflection spacer.

Accordingly, the controller 190 can: read resistance values from the setof sensor traces; interpret a force magnitude of the input applied tothe touch sensor surface based on resistance values read from the set ofsensor traces; and drive the oscillating voltage across the multi-layerinductor during the haptic feedback cycle in response to the forcemagnitude of the input exceeding a threshold force.

For example, a first spring element—in the array of spring elements162—can yield to an input applied to a first region of the touch sensorsurface proximal the first spring element at a first time. A firstdeflection spacer—in the set of deflection spacers 160—can then:compress between the first spring element and a first support location,in the array of support locations, on the bottom layer of the substrate;and exhibit a decrease in local contact resistance proportional to aforce magnitude of the input. Accordingly, the controller 190 can:detect a first change in resistance value across a first sensor trace,adjacent the first deflection spacer, at the first time; and interpretthe force magnitude of the input, partially carried by the first springelement, based on the first change in resistance value.

6.3.4.1 Capacitive Touch+Resistive Force

More specifically, in the variation of the system 100 described abovethat incudes an array of drive electrodes and sense electrodes that forma capacitive touch sensor across the top layer of the substrate 102, thecontroller 190 can: read capacitance values from the capacitive touchsensor and resistance values from the set of pressure sensors during ascan cycle; and fuse these data into a location and force magnitude of atouch input on the touch sensor surface 172 during this scan cycle.

For example, during a scan cycle, the controller 190 can: read a set ofcapacitance values (e.g., change in capacitance charge times, dischargetimes, or RC-circuit resonant frequencies) between drive electrodes andsense electrodes in the capacitive touch sensor; read a set ofresistance values across electrode pairs 105 in the array of electrodepairs 105; detect a lateral position and a longitudinal position of atouch input on the touch sensor surface 172 based on the set ofcapacitance values (e.g., based on changes in capacitance values betweendrive electrodes and sense electrodes at known lateral and longitudinalpositions across the top layer of the substrate 102); interpret a forcemagnitude of the touch input based on the set of resistance values, asdescribed above; and output the lateral position, the longitudinalposition, and the force magnitude of the touch input, such as in theform of a force-annotated touch image.

Therefore, in this example, if the controller 190 detects a single touchinput on the touch sensor surface 172 during this scan cycle based onthe set of capacitance values, the controller 190 can attribute theentire applied force to this singular touch input. Accordingly, thecontroller 190 can: implement methods and techniques described above tocalculate individual forces carried by each spring element 162 based onresistance values read from the adjacent electrode pairs 105, storedbaseline resistance values for these electrode pairs 105, and storedforce models for these springs elements; sum these individual forces tocalculate a total force applied to the touch sensor surface 172 duringthis scan cycle; and label the location of the touch input—derived fromthe set of capacitance values—with this total force.

6.3.5 Capacitive Force Sensor

In this variation and as described above, the substrate canalternatively include a bottom layer: arranged below the second layeropposite the first layer; and comprising a set of sensor traces arrangedat the set of discrete deflection spacer locations. The system 100 canalso include a coupling plate 168 configured to: couple to the chassisadjacent the array of spring elements; and effect (e.g., modify, change)capacitance values of (e.g., within) the set of sensor traces responsiveto displacement of the substrate toward the coupling plate 168.

In this variation, the array of spring elements and the coupling plate168 can form a unitary metallic structure: arranged between thesubstrate and the chassis; defining a nominal plane; and defining anarray of capacitive coupling regions adjacent the set of discretedeflection spacer locations. Each spring element therefore: can beformed in the unitary metallic structure; can extend from a capacitivecoupling region, in the array of capacitive coupling regions; and can beconfigured to return toward the nominal plane in response to absence ofinputs applied to the touch sensor surface. Furthermore, each sensortrace: can capacitively couple to an adjacent capacitive couplingregion, in the array of capacitive coupling regions, of the unitarymetallic structure; and can move toward the adjacent capacitive couplingregion in response to application of inputs on the touch sensor surfaceproximal the sensor trace.

Accordingly, in this variation, the controller can: read capacitancevalues from the set of sensor traces; interpret a force magnitude of theinput applied to the touch sensor surface based on capacitance valuesread from the set of sensor traces; and drive the oscillating voltageacross the multi-layer inductor during the haptic feedback cycle inresponse to the force magnitude of the input exceeding a thresholdforce. For example, a first spring element—in the array of springelements—can yield to a touch input applied to a first region of thetouch sensor surface proximal the first spring element at a first time.Accordingly, a first sensor trace—adjacent the first region of the touchsensor surface—moves toward a first capacitive coupling region by adistance proportional to a force magnitude of the input. Accordingly,the controller: detects a first change in capacitance value of the firstsensor trace at the first time; interpret the force magnitude of theinput based on the first change in capacitance value; and executes ahaptic feedback cycle in response to the force magnitude of the inputexceeding the threshold force.

In another example, the controller can: read capacitance values from theset of sensor traces at a scan frequency during a first time period; andinterpret the force magnitude of the input applied to the touch sensorsurface based on capacitance values read from the drive and senseelectrode pairs during the first time period. Then, in response to theforce magnitude of the input exceeding the threshold force, thecontroller can: drive an oscillating voltage across the multi-layerinductor during the haptic feedback cycle, following the first timeperiod; and pause reading electrical values from the set of drive andsense electrode pairs during the haptic feedback cycle. The controllercan then resume reading capacitance values from the sensor tracesfollowing completion of the haptic feedback cycle.

6.3.5.1 Mutual-Capacitance Sensors

In this variation, each sensor trace at a deflection spacer location onthe bottom layer of the substrate can form a capacitance sensor arrangedin a mutual-capacitance configuration, as shown in FIG. 23.

For example, each sensor trace 146 can include: a drive electrodearranged on the bottom layer of the substrate 102 adjacent a first sideof a support location; and a sense electrode arranged on the bottomlayer of the substrate 102 adjacent a second side of the supportlocation opposite the drive electrode. In this example, the driveelectrodes and sense electrodes within a sensor trace 146 cancapacitively couple, and an air gap between the substrate 102 and thecoupling plate 168 can form an air dielectric between the driveelectrodes and sense electrodes. When the touch sensor surface 172 isdepressed over a sensor trace 146, the adjacent spring element 162 canyield, thereby moving the drive electrodes and sense electrodes of thesensor trace 146 closer to the coupling plate 168 and reducing the airgap between these drive electrodes and sense electrodes. Because thecoupling plate 168 exhibits a dielectric greater than air, the reduceddistance between the coupling plate 168 and the substrate 102 thusincreases the effective dielectric between the drive electrodes andsense electrodes and thus increases the capacitance of the driveelectrodes and sense electrodes. The capacitance value of the sensortrace 146 may therefore deviate from a baseline capacitance value—suchas in the form of an increase in the charge time of the sensor trace146, an increase in the discharge time of the sensor trace 146, or adecrease in the resonant frequency of the sensor trace 146—when thetouch sensor surface 172 is depressed over the sensor trace 146.

Therefore, in this implementation, the controller 190 can, during a scancycle: drive the coupling plate 168 to a reference (e.g., ground)potential; (serially) drive each drive electrode in the sensor traces146, such as a target voltage, over a target time interval, or with analternating voltage of a particular frequency; read a set of capacitancevalues—from the sense electrodes in the array of sensor traces 146—thatrepresent measures of mutual capacitances between drive electrodes andsense electrodes of these sensor traces 146; and interpret adistribution of forces applied to the touch sensor surface 172 based onthis set of capacitance values and known spring constants of the arrayof spring elements 162, as described below.

6.3.5.2 Self-Capacitance Sensors

In another implementation, the sensor traces 146 are arranged in aself-capacitance configuration adjacent each support location.

For example, each sensor trace 146 can include a single electrodearranged on the bottom layer of the substrate 102 adjacent (e.g.,encircling) a support location, and the coupling plate 168 can functionas a common second electrode for each sensor trace 146. In this example,the single electrode within a sensor trace 146 and the coupling plate168 can capacitively couple, and an air gap between the substrate 102and the coupling plate 168 can form an air dielectric between the sensortrace 146 and the coupling plate 168. When the touch sensor surface 172is depressed over the sensor trace 146, the adjacent spring element 162can yield, thereby: moving the sensor trace 146 closer to the couplingplate 168; reducing the air gap between the sensor trace 146 and thecoupling plate 168; and increasing the capacitance between the sensortrace 146 and the coupling plate 168. The capacitance value of thesensor trace 146 may therefore deviate from a baseline capacitancevalue—such as in the form of an increase in the charge time of thesensor trace 146, an increase in the discharge time of the sensor trace146, or a decrease in the resonant frequency of the sensor trace146—when the touch sensor surface 172 is depressed over the sensor trace146.

Therefore, in this implementation, the controller 190 can, during a scancycle: drive the coupling plate 168 to a reference (e.g., ground)potential; (serially) drive each sensor trace 146, such as a targetvoltage, over a target time interval, or with an alternating voltage ofa particular frequency; read a set of capacitance values—from the arrayof sensor traces 146—that represent measures of self capacitancesbetween the sensor traces 146 and the coupling plate 168; and interpreta distribution of forces applied to the touch sensor surface 172 basedon this set of capacitance values and known spring constants of thearray of spring elements 162, as described below.

6.3.5.3 Separate Coupling Plate Between Spring Plate and Substrate

The coupling plate 168 is configured to: couple to the chassis adjacentthe array of spring elements 162; and effect capacitance values of thearray of sensor traces 146 responsive to displacement of the substrate102 toward the coupling plate 168.

In one implementation shown in FIG. 21, the coupling plate 168 defines adiscrete structure interposed between the chassis interface 166 and thesubstrate 102 and rigidly mounted to the chassis of the computingdevice.

Generally, in this implementation, the coupling plate 168: can beinterposed between the array of spring elements 162 and the substrate102; can include an array of perforations aligned (e.g., coaxial) withthe array of support locations and the array of spring elements 162 anddefining geometries similar to (and slightly larger than) the stages onthe spring elements 162; and define an array of capacitive couplingregions adjacent (e.g., encircling) the array of perforations. Forexample, the coupling plate 168 can include a thin-walled structure(e.g., a stainless steel 20-gage, or 0.8-millimeter-thick sheet) that ispunched, etched, or laser-cut to form the array of perforations. In thisimplementation, each sensor trace 146 (e.g., drive electrodes and senseelectrodes in the mutual capacitance configuration, a single electrodein the self capacitance configuration) can extend around a supportlocation on the bottom layer of the substrate 102, such as up to aperimeter of the adjacent perforation in the coupling plate 168 suchthat the sensor trace 146 (predominantly) capacitively couples to theadjacent capacitive coupling region on the coupling plate 168 ratherthan the adjacent spring element 162.

Furthermore, in this implementation, the system 100 can further includea set of deflection spacers 160, each of which: extends through aperforation in the coupling plate 168; is (slightly) undersized for theperforation; and couples an adjacent support location on the bottomlayer of the substrate 102 to an adjacent spring element 162 in thechassis interface 166. For example, each deflection spacer 160 caninclude a silicone coupon bonded (e.g., with a pressure-sensitiveadhesive) to the stage of an adjacent spring element 162 on one side andto the adjacent support location on the substrate 102 on the opposingside.

Therefore, in this implementation, each sensor trace 146 can:capacitively couple to an adjacent capacitive coupling region of thecoupling plate 168; and move toward the adjacent capacitive couplingregion on the coupling plate 168 in response to application of a forceon the touch sensor surface 172 proximal the sensor trace 146, whichyields a change in the capacitance value of the sensor trace 146representative of the portion of the force of this input carried theadjacent spring element 162. More specifically, because the couplingplate 168 is rigid and mechanically isolated from the substrate 102 andthe spring elements 162, the capacitive coupling regions of the couplingplate 168 can remain at consistent positions offset above the chassisreceptacle such that application of a force to the touch sensor surface172 compresses all or a subset of the spring elements 162, moves all ora subset of the sensor traces 146 closer to their correspondingcapacitive coupling regions, and repeatably changes the capacitancevalues of these sensor traces 146 as a function of (e.g., proportionalto) the force magnitudes carried by the spring elements 162, which thecontroller 180 can then interpret to accurately estimate these forcemagnitudes, the total force applied to the touch sensor surface 172,and/or force magnitudes of individual touch inputs applied to the touchsensor surface 172.

Furthermore, in this implementation, the deflection spacer 160 candefine a height approximating (or slightly greater than) a height of themaximum vertical compression of the adjacent spring element 162corresponding to a target dynamic range of the adjacent sensor trace146. For example, for a target dynamic range of 2 Newtons (e.g., 200grams) for a pressure sensor given a maximum of one millimeter ofvertical displacement of the touch sensor surface 172—and therefore amaximum of one millimeter of compression of the adjacent spring element162—the spring element 162 can be tuned for a spring constant of 2000Newtons per meter. Furthermore, the deflection spacer 160 can be of aheight of approximately one millimeter, plus the thickness of thecoupling plate 168 and/or a stack tolerance (e.g., 10%, of 0.1millimeter).

In this implementation, the coupling plate 168 and the chassis interface166 can be fastened directly to the chassis of the computing device.Alternatively, the coupling plate 168 and the chassis interface 166 canbe mounted (e.g., fastened, riveted, welded, crimped) to a separateinterface plate that is then fastened or otherwise mounted to thechassis. The system 100 can also include a non-conductive buffer layerarranged between the chassis interface 166 and the coupling plate 168,as shown in FIG. 21, in order to electrically isolate the chassisinterface 166 from the coupling plate 168.

6.3.5.4 Integral Coupling Plate and Spring Plate

In another implementation, the coupling plate 168 and the chassisinterface 166 define a single unitary (e.g., metallic) structurearranged between the substrate 102 and the chassis, as shown in FIGS. 20and 21.

Generally, in this implementation, the unitary metallic structure candefine: a nominal plane between the chassis receptacle and the substrate102; and an array of capacitive coupling regions adjacent (e.g., alignedto, coaxial with) the array of support locations on the substrate 102.In this implementation, each spring element 162: can be formed in theunitary metallic structure (e.g., by etching, laser cutting); can extendfrom its adjacent capacitive coupling region; can define a stage coupledto the corresponding support location on the bottom layer of thesubstrate 102 (e.g., via a deflection spacer 160 as described above);and can be configured to return to approximately the nominal plane inresponse to absence of a touch input applied to the touch sensor surface172.

When the unitary structure is rigidly mounted to the chassis of thecomputing device, the unitary structure can thus rigidly locate thecapacitive coupling regions relative to the chassis and within (orparallel to) the nominal plane, and the stages of the spring elements162 can move vertically relative to the nominal plane and the capacitivecoupling regions.

Thus, each sensor trace 146 on the substrate 102 can: capacitivelycouple to an adjacent capacitive coupling region on the unitary metallicstructure; and move toward this adjacent capacitive coupling region inresponse to application of a force on the touch sensor surface 172proximal the sensor trace 146, which thus changes the capacitance valueof the sensor trace 146 proportional to compression of the adjacentspring element 162 and therefore proportional to the portion of theforce carried by the spring element 162.

Furthermore, in this implementation, the unitary metallic structure canbe fastened directly to the chassis of the computing device.Alternatively, the unitary metallic structure can be mounted (e.g.,fastened, riveted, welded, crimped) to a separate chassis interface 190that is then fastened or otherwise mounted to the chassis.

6.4 Sliding Interface

In another implementation shown in FIG. 10B, the substrate 102 rests onand slides over a bearing surface in the base of the receptacle 194,such as: a continuous, planar bearing surface; a discontinuous, planarbearing surface (e.g., a planar surface with relief channels to reducestiction between the substrate 102 and the bearing surface); or a set ofbushings (e.g., polymer pads) or bearings (e.g., steel ball-bearings)offset above and distributed across the base of the receptacle 194.

In one example: the receptacle 194 defines a planar base surfaceparallel to the vibration plane; the set of magnetic elements isretained in the base of the receptacle 194 below the planar basesurface; and the substrate 102 includes a rigid (e.g., a fiberglass) PCBarranged over and in contact with the planar base surface, is configuredto slide over the planar base surface parallel to the vibration plane,and is configured to transfer a vertical force in applied to the touchsensor surface 172 into the chassis 192.

In this configuration: the set of magnetic elements can be embedded inthe base of the receptacle 194; and the system 100 can further include alow-friction layer interposed between the base of the receptacle 194 andthe substrate 102. In particular, the low-friction layer can beconfigured: to prevent direct contact between the magnet elements andthe bottom spiral trace of the multi-layer inductor 150 on the bottomlayer 140 of the substrate 102; and to facilitate smooth oscillation ofthe substrate 102—and the touch sensor assembly more generally—over thebase of the receptacle 194. For example, the low-friction layer caninclude a polytetrafluoroethylene (or “PTFE”) film arranged between theset of magnetic elements and the multi-layer inductor 150.Alternatively, the low-friction layer can be arranged across the innerface of the substrate 102 and over the multi-layer inductor 150.

Furthermore, in this configuration, the system 100 can include a springelement 162 configured to center the substrate 102 within the receptacle194 responsive to depolarization of the multi-layer inductor 150 duringa haptic feedback cycle. In another example, the system 100 can includea flexure coupled to or physically coextensive with the substrate 102,extending onto and retained at the chassis 192, and thus functioning tore-center the touch sensor assembly relative to the set of magneticelements upon conclusion of a haptic feedback cycle. In yet anotherexample, in this configuration (and in the foregoing configurations),the system 100 can include a flexible membrane (e.g., a seal) locatedproximal a perimeter of the touch sensor surface 172, interposed betweenthe touch sensor and an interior wall of the receptacle 194, andconfigured to seal an interstice between the touch sensor and thereceptacle 194, such as from moisture and/or dust ingress.

7. Ground Plane Geometry and Shielding

The substrate 102 can further include a shielding trace fabricated in aconductive layer and configured to shield the touch sensor fromelectrical noise generated by the multi-layer inductor 150, such asduring and after a haptic feedback cycle.

In one implementation, the substrate 102 further includes anintermediate layer 106 interposed between: the top layer 104, whichcontains the drive and sense electrode pairs 105; and the first layer110 of the substrate 102 that contains the topmost spiral trace of themulti-layer inductor 150. In this implementation, the intermediate layer106 can include a contiguous trace area that defines an electricalshield 107 configured to shield the set of drive and sense electrodepairs 105 of the touch sensor from electrical noise generated by themulti-layer inductor 150 when driven with an oscillating voltage by thecontroller 190 during a haptic feedback cycle. In particular, thecontroller 190 can drive the electrical shield 107 in the intermediatelayer 106 to a reference voltage potential (e.g., to ground, to anintermediate voltage), such as: continuously throughout operation; orintermittently, such as during and/or slightly after a haptic feedbackcycle. Thus, when driven to the reference potential, the electricalshield 107 can shield the drive and sense electrode pairs 105 of thetouch sensor in the top layer 104 from electrical noise.

Furthermore, as shown in FIG. 1, the electrical shield 107 can include acleft—such as in the form of a serpentine break across the width of theelectrical shield 107—in order to prevent circulation of Eddy currentswithin the electrical shield 107, which may otherwise: create noise atthe drive and sense electrode pairs 105 in the touch sensor above;and/or induce a second magnetic field opposing the magnetic fieldgenerated by the multi-layer inductor 150, which may brake oscillationof the substrate 102 during a haptic feedback cycle.

Additionally or alternatively, in the configuration described above inwhich the system 100 includes sensor traces 146 at deflection spacelocations on the bottom layer 140 of the substrate 102, the first layer110 of the substrate 102—arranged below the top layer 104 and/or theintermediate layer 106 and containing the first spiral trace 11 of themulti-layer inductor 150—can include an electrical shield 107 separatefrom and encircling the first spiral trace 11. In this implementation,the controller 190 can drive both this electrical shield 107 in thefirst layer 110 and the multi-layer inductor 150 to a reference voltagepotential (e.g., to ground, to an intermediate voltage)—outside ofhaptic feedback cycles—in order to: shield these sensor traces 146 fromelectrical noise from outside of the system 100; and/or shield the driveand sense electrode pairs 105 in the touch sensor from electrical noisegenerated by these sensor traces 146. Therefore in this implementation,the first layer 110 of the substrate 102—containing the first spiraltrace 111 of the multi-layer inductor 150—can further include a shieldelectrode trace 112 adjacent and offset from the first spiral trace nil;and the controller 190 can drive the shield electrode trace 112 and thefirst spiral trace 111 to a reference potential in order to shield thesecond set of sensor traces 146—at the deflection spacer locations—fromelectrical noise when reading electrical values from these sensor traces146.

For example, in this implementation, the controller 190 can hold themulti-layer inductor 150 (or a topmost spiral trace in the multi-layerinductor 150) at a virtual ground potential while scanning andprocessing resistance (or capacitance) data from drive and senseelectrode pairs 105 in the touch sensor in the top conductive layer(s)of the substrate 102 during a scan cycle. The controller 190 cansubsequently: detect an input on the touch sensor surface 172 based on achange in resistance (or capacitance) values read from drive and senseelectrode pairs 105 in the touch sensor; release the multi-layerinductor 150 from the virtual reference potential; and polarize themulti-layer inductor 150 via a time-varying current signal during ahaptic feedback cycle responsive to detecting this input on the touchsensor surface 172. More specifically, the controller 190 can: groundthe electrical shield 107 and the multi-layer inductor 150 during a scancycle in order to shield the touch sensor from electronic noise; andpause scanning of the touch sensor during haptic feedback cycles (e.g.,while the multi-layer inductor 150 is polarized) in order to avoidgenerating and responding to noisy touch images during haptic feedbackcycles.

Thus, in this variation, power electronics (e.g., the multi-layerinductor 150) and sensor electronics in both high- and low-resolutionsensors (e.g., drive and sense electrode pairs 105 in the touch sensorand sensor traces 146 at the deflection spacer locations, respectively)can be fabricated on a single, unitary substrate 102, therebyeliminating manufacture and assembly of multiple discrete substrates fordifferent haptic feedback and touch-sensing functions and enable thesystem 100 to perform touch sensing, force-sensing, and haptic feedbackfunctions in a thinner package.

8. Controller

During operation, the controller 190 can: detect application of an inputon the touch sensor surface 172 based on changes in electrical (e.g.,capacitance or resistance, etc.) values between drive and senseelectrode pairs 105 in the touch sensor integrated into the top layer(s)104 of the substrate 102; characterize a force magnitude of the inputbased on these electrical values read from the touch sensor and/or basedon electrical values read from sensor traces 146 in the deflectionspacers 160 integrated into the bottom layer(s) 140 of the substrate102; and/or interpret the input as a “click” input if the forcemagnitude of the input exceeds a threshold force magnitude (e.g., 160grams). Then, in response to detecting the input and/or interpreting theinput as a “click” input, the controller 190 can execute a hapticfeedback cycle, such as by transiently polarizing the multi-layerinductor 150 in order to induce alternating magnetic coupling betweenthe multi-layer inductor 150 and the set of magnetic elements and thusvibrating the substrate 102 within the chassis 192, serving hapticfeedback to a user, and providing the user with tactile perception ofdownward travel of the touch sensor surface 172 analogous to depressionof a mechanical momentary switch, button, or key.

8.1 Controller Mounted to Substrate

In the foregoing configurations: the controller 190 (and/or a driver) ismounted to the substrate 102, such as opposite the touch sensor (on theinner face of the substrate 102); and the system 100 further includes aflexible circuit extending between the substrate 102 and the chassis 192and electrically coupled to a power supply arranged in the chassis 192.Thus, in this configuration, the controller 190 can: read electricalvalues between drive and sense electrode pairs 105 in the touch sensoror otherwise sample the adjacent touch sensor directly; generate asequence of touch images based on these electrical values between driveand sense electrode pairs 105 in the touch sensor; and then output thissequence of touch images to a processor arranged in the chassis 192 viathe flexible circuit. Furthermore, the driver can intermittently sourcecurrent from the power supply to the multi-layer inductor 150 via theflexible circuit responsive to triggers from the adjacent controller190. Thus, in this configuration, the touch sensor assembly can includethe substrate 102, the touch sensor, (the touch sensor surface 172,) thecontroller 190, the driver, the multi-layer inductor 150, and theflexible circuit in a self-contained unit. This self-contained unit canthen be installed over a receptacle 194 in a chassis 192 and theflexible circuit can be connected to a power and data port in thereceptacle 194 to complete assembly of the system 100 into this device.

9. Haptic Feedback Cycle

In this variation, the multi-layer inductor 150—integrated into thesubstrate 102—and the set of magnetic elements—housed within the chassis192 below the multi-layer inductor 150—cooperate to define a compact,integrated multi-layer inductor 150 configured to oscillate thesubstrate 102 and the touch sensor surface 172 responsive topolarization of the multi-layer inductor 150 by the controller 190(e.g., in response detecting touch inputs on the touch sensor surface172). More specifically, the controller 190, in conjunction with a drivecircuit, can supply an alternating (i.e., time-varying) drive current tothe multi-layer inductor 150 during a haptic feedback cycle, therebygenerating a time-varying magnetic field through the multi-layerinductor 150 that periodically reverses direction. Thus, the controller190 and/or the drive circuit can transiently polarize the multi-layerinductor 150 to generate magnetic forces between the multi-layerinductor 150 and the set of magnetic elements, thereby causing themulti-layer inductor 150 (and thus the substrate 102 and touch sensorsurface 172) to be alternately attracted and repelled by poles of theset of magnetic elements and oscillating the touch sensor surface 172relative to the chassis 192, as shown in FIGS. 16 and 17.

In particular, in response to detecting a touch input—on the touchsensor surface 172—that exceeds a threshold force (or pressure)magnitude, the controller 190 drives the multi-layer inductor 150 duringa “haptic feedback cycle” in order to tactilely mimic actuation of amechanical snap button, as shown in FIGS. 16 and 17. For example, inresponse to such a touch input, the controller 190 can trigger a motordriver to drive the multi-layer inductor 150 with a square-wavealternating voltage for a target click duration (e.g., 250milliseconds), thereby inducing an alternating magnetic field throughthe multi-layer inductor 150, which magnetically couples to the set ofmagnetic elements, induces an oscillating force between the magneticelement and the multi-layer inductor 150, and oscillates the substrate102 relative to the chassis 192 of the device.

9.1 Paused Scanning During Haptic Feedback Cycle

In one implementation, the controller 190: reads electrical values fromthe set of drive and sense electrode pairs 105 during scan cycles at ascan frequency (e.g., 200 Hz) during operation; and interprets inputs onthe touch sensor surface 172 (and their force magnitudes) based on a setof electrical values read from the drive and sense electrode pairs 105during each scan cycle. Then, in response to detecting an input on thetouch sensor surface 172 (or detecting an input of force magnitudegreater than a threshold force on the touch sensor surface 172) duringthe current scan cycle, the controller 190: drives an oscillatingvoltage across the multi-layer inductor 150 during a haptic feedbackcycle following the current scan cycle; pauses reading electrical valuesfrom the set of drive and sense electrodes during the haptic feedbackcycle; and then resumes reading electrical values from the set of driveand sense electrodes—and interpreting inputs on the touch sensor surface172 based on these electrical values—following completion of the hapticfeedback cycle.

Generally, in this implementation, the controller 190 can: execute asequence of scan cycles to detect and characterize force magnitudes ofinputs applied over the touch sensor surface 172 during these scancycles; pause scanning of the touch sensor (and or the deflectionspacers 160) while executing a haptic feedback cycle in response todetecting an input exceeding a threshold force magnitude; and thenresume scanning of the touch sensor upon completion of the hapticfeedback cycle.

More specifically, during a scan cycle, the controller 190 can: drivethe multi-layer inductor 150 to a ground potential; sample capacitance(or resistance) values between drive and sense electrode pairs in thetouch sensor; transform these values into locations (and forcemagnitudes) of inputs applied over the touch sensor surface 172 duringthe scan cycle; sample resistance (or capacitance) values from the setof deflection spacers 160; interpret force magnitudes of these inputs onthe touch sensor surface 172; and generate a touch image representingboth the locations and force magnitudes of these inputs on the touchsensor surface 172.

Then, in response to the force magnitude of a detected input exceeding athreshold force magnitude (e.g., a “click” force of 160 grams), thecontroller 190 can: release the multi-layer inductor 150 from the groundpotential; and trigger the drive circuit to polarize the multi-layerinductor 150 according to a particular AC waveform (e.g., selected basedon the threshold force magnitude) to induce oscillation of the touchsensor surface 172 relative to the chassis 192 during a haptic feedbackcycle (or a “haptic feedback cycle”). The controller 190 can also pausescanning of the touch sensor prior to or during the haptic feedbackcycle. The controller 190 can then resume executing scan cycles at thetouch sensor and/or the deflection spacers 160 after completion of thehaptic feedback cycle (e.g., once the multi-layer inductor 150 isdepolarized and/or returned to ground potential).

9.2 Interleaved Scanning and Haptic Feedback Cycle

Alternatively, after detecting an input on the touch sensor surface 172(or after detecting an input of force magnitude greater than a thresholdforce on the touch sensor surface 172) during the current scan cycle,the controller 190 can: drive the multi-layer inductor 150 with anoscillating voltage at a first frequency (e.g., 50 Hz); and interleavehigher-frequency (e.g., 200 Hz) scan cycles between intervals of peakmagnetic field coupling between the multi-layer inductor 150 and themagnetic elements during this haptic feedback cycle. For example, inthis implementation, the controller 190 can continue to captureelectrical values from drive and sense electrode pairs 105 in the touchsensor and detect and track inputs on the touch sensor surface 172during a haptic feedback cycle by interleaving scan cycles at the touchsensor between voltage reversals across the multi-layer inductor 150during this haptic feedback cycle.

In this implementation, the controller 190 can: read electrical valuesfrom the set of drive and sense electrode pairs 105 during scan cyclesat a scan frequency (e.g., 200 Hz) during operation; and interpretinputs on the touch sensor surface 172 (and their force magnitudes)based on a set of electrical values read from the drive and senseelectrode pairs 105 during each scan cycle. Then, in response todetecting an input on the touch sensor surface 172 (or detecting aninput of force magnitude greater than a threshold force on the touchsensor surface 172) during the current scan cycle, the controller 190:drives an oscillating voltage, at a feedback frequency (e.g., 50 Hz)less than the scan frequency, across the multi-layer inductor 150 duringa haptic feedback cycle; intermittently reads electrical values from theset of drive and sense electrodes at the scan frequency—between voltagereversals across the multi-layer inductor 150 at the feedbackfrequency—during the haptic feedback cycle; interprets inputs on thetouch sensor surface 172 during the haptic feedback cycle based on theseintermittent electrical values; and returns to reading electrical valuesfrom the set of drive and sense electrode pairs 105 at the scanfrequency following completion of the haptic feedback cycle.

9.3 Preset Force Threshold

As described above, the controller 190 can execute a haptic feedbackcycle in response to detecting a touch input on the touch sensor surface172 that meets or exceeds one or more preset force thresholds in BlockS120. For example, the controller 190 can initiate a haptic feedbackcycle in response to detecting a touch input on the touch sensor surface172 that exceeds a threshold force (or pressure) magnitude correspondingto tuned break forces (or pressures) of mechanical buttons of commonuser input devices (e.g., mechanical keys keyboard, mechanical volumeand home buttons on smartphones, buttons on physical computer mice, amechanical trackpad button or snapdome), such as 165 grams. Therefore,the controller 190 can selectively execute a haptic feedback cycle inresponse to detecting an input on the touch sensor surface 172 thatexceeds this threshold force in order to emulate haptic feedback of suchmechanical buttons.

9.4 User-Elected Force Threshold

Alternatively, the controller 190 can implement a user-customized forcethreshold to trigger a haptic feedback cycle, such as based on a userpreference for greater input sensitivity (corresponding to a lower forcethreshold) or based on a user preference for lower input sensitivity(corresponding to a greater force threshold) set through a graphicaluser interface executing on a computing device connected to orincorporating the system 100.

9.5 Variable Force Threshold

In another implementation, the controller 190 can segment the touchsensor surface 172 into two or more active and/or inactive regions, suchas based on a current mode or orientation of the system 100, asdescribed below, and the controller 190 can discard an input on aninactive region of the touch sensor surface 172 but initiate a hapticfeedback cycle in response to detecting a touch input of sufficientforce magnitude within an active region of the touch sensor surface 172.

In this implementation, the controller 190 can additionally oralternatively assign unique threshold force (or pressure) magnitudes todiscrete regions of the touch sensor surface 172 and selectively executehaptic feedback cycles responsive to inputs—on various regions of thetouch sensor surface 172—that exceed threshold force magnitudes assignedto these individual regions of the touch sensor surface 172. Forexample, the controller 190 can: assign a first threshold magnitude to aleft-click region of the touch sensor surface 172; and assign a secondthreshold magnitude—greater than the first threshold magnitude in orderto reject aberrant right-clicks on the touch sensor surface 172—to aright-click region of the touch sensor surface 172. In this example, thecontroller 190 can also: assign a third threshold magnitude to a centerscroll region of the touch sensor surface 172, wherein the thirdthreshold magnitude is greater than the first threshold magnitude inorder to reject aberrant scroll inputs on the touch sensor surface 172;but also link the center scroll region to a fourth threshold magnitudefor a persistent scroll event, wherein the fourth threshold magnitude isless than the first threshold magnitude.

9.6 Standard Click and Deep Click

In one variation shown in FIG. 19, the controller 190: executes a“standard-click haptic feedback cycle” in Blocks Silo and S120 inresponse to application of a force that exceeds a first force magnitudeand that remains less than a second force threshold (hereinafter a“standard click input”); and executes a “deep haptic feedback cycle” inBlocks S114 and S124 in response to application of a force that exceedsthe second force threshold (hereinafter a “deep click input”). In thisvariation, during a deep haptic feedback cycle, the controller 190 candrive the multi-layer inductor 150 for an extended duration of time(e.g., 750 milliseconds), at a higher amplitude (e.g., by driving thehaptic feedback cycle at a higher peak-to-peak voltage), and/or at adifferent (e.g., lower) frequency in order to tactilely indicate to auser that a deep click input was detected at the touch sensor surface172.

In one example, the controller 190 can: output a left-click controlcommand and execute a standard-click haptic feedback cycle in responseto detecting an input of force magnitude between a low “standard” forcethreshold and a high “deep” force threshold; and output a right-clickcontrol command function and execute a deep-haptic feedback cycle inresponse to detecting an input of force magnitude greater than the high“deep” force threshold. The system 100 can therefore: detect inputs ofdifferent force magnitudes on the touch sensor surface 172; assign aninput type to an input based on its magnitude; serve different hapticfeedback to the user by driving the multi-layer inductor 150 accordingto different schema based on the type of a detected input; and outputdifferent control functions based on the type of the detected input.

9.7 Hysteresis

In one variation shown in FIG. 18, the controller 190 implementshysteresis techniques to trigger haptic feedback cycles duringapplication and retraction of a single input on the touch sensor surface172. In particular, in this variation, the controller 190 canselectively: drive the multi-layer inductor 150 according to a“down-click” oscillation profile during a haptic feedback cycle inresponse to detecting a new input—of force greater than a high forcethreshold (e.g., 165 grams)—applied to the touch sensor surface 172;track this input in contact with the touch sensor surface 172 overmultiple scan cycles; and then drive the multi-layer inductor 150according to an “up-click” oscillation profile during a later hapticfeedback cycle in response to detecting a drop in force magnitude ofthis input to less than a low force threshold (e.g., 60 grams).Accordingly, the system 100 can: replicate the tactile “feel” of amechanical snap button being depressed and later released; and prevent“bouncing” haptic feedback when the force magnitude of an input on thetouch sensor surface 172 varies around the force threshold.

More specifically, when the force magnitude of an input on the touchsensor surface 172 reaches a high force threshold, the controller 190can execute a single “down-click”haptic feedback cycle—suggestive ofdepression of a mechanical button—until the input is released from thetouch sensor surface 172. However, the controller 190 can also executean “up-click” haptic feedback cycle—suggestive of release of a depressedmechanical button—as the force magnitude of this input drops below asecond, lower threshold magnitude. Therefore, the controller 190 canimplement hysteresis techniques to prevent “bouncing” in hapticresponses to the inputs on the touch sensor surface 172, to indicate toa user that a force applied to the touch sensor surface 172 has beenregistered (i.e., has reached a first threshold magnitude) throughhaptic feedback, and to indicate to the user that the user's selectionhas been cleared and force applied to the touch sensor surface 172 hasbeen registered (i.e., the applied force has dropped below a secondthreshold magnitude) through additional haptic feedback.

10. Multiple Multi-Layer Inductors

In one variation, the system 100 can also include multiple multi-layerinductor 150 and magnetic element pairs. In one example, the system 100includes: a first multi-layer inductor 150 arranged proximal a firstedge of the substrate 102; and a first magnetic element 181 arranged inthe chassis 192 under the first multi-layer inductor 150 and thus nearthe first edge of the substrate 102. In this example, the system 100 canalso include: a second magnetic element 182 rigidly coupled to thechassis 192 and offset from the first magnetic element 181; and a secondinductor coupled to the substrate 102 below the touch sensor surface172, arranged proximal a second edge of the substrate 102 opposite thefirst edge, and configured to magnetically couple to the second magneticelement 182. Furthermore, in this example, the controller 190 can:selectively polarize the first multi-layer inductor 150 responsive todetection of the touch input on the touch sensor surface 172 proximalthe first edge of the substrate 102 to oscillate the substrate 102 inthe vibration plane relative to the chassis 192 with peak energyperceived proximal this first edge of the substrate 102; and selectivelypolarize the second inductor responsive to detection of a second touchinput on the touch sensor surface 172 proximal the second edge of thesubstrate 102 to oscillate the substrate 102 in the vibration planerelative to the chassis 192 with peak energy perceived proximal thissecond edge of the substrate 102.

In a similar implementation, the system 100 can include a firstmulti-layer inductor 150—as described above—and a secondinductor/magnetic element pair that cooperates with the firstinductor-magnetic element pair to oscillate the substrate 102. In thisvariation, the first inductor-magnetic element pair can include a coilmounted to the substrate 102 offset to the right of the center of massof the substrate 102 by a first distance. The first inductor-magneticelement pair can also include an array of magnets aligned in a row underthe multi-layer inductor 150. The array of magnets can cooperate withthe multi-layer inductor 150 of the first inductor-magnetic element pairto define an axis of vibration of the first inductor-magnetic elementpair. The second inductor-second magnetic element 182 pair can include acoil mounted to the substrate 102 offset to the left of the center ofmass of the substrate 102 by a second distance. The secondinductor-second magnetic element 182 pair can also include an array ofmagnets aligned in a row. The array of magnets can cooperate with themulti-layer inductor 150 of the second inductor-second magnetic element182 pair to define an axis of vibration of the second inductor-secondmagnetic element 182 pair.

In one implementation, the array of magnets of the firstinductor-magnetic element pair can be arranged in a row parallel thearray of magnets of the second inductor-second magnetic element 182 pairsuch that the axis of vibration of the first inductor-magnetic elementpair is parallel to the axis of vibration of the second inductor-secondmagnetic element 182 pair. In this implementation, the multi-layerinductor 150 of the first inductor-magnetic element pair can be mountedto the substrate 102 offset from the center of mass of the substrate 102by the first distance equal to the second distance between themulti-layer inductor 150 of the second inductor-second magnetic element182 pair and the center of mass. Therefore, a midpoint between themulti-layer inductor 150 of the first inductor-magnetic element pair andthe multi-layer inductor 150 of the second inductor-second magneticelement 182 pair can be coaxial with the center of mass. Therefore, thefirst inductor-magnetic element pair and second inductor-second magneticelement 182 pair can cooperate to vibrate the substrate 102 along anoverall axis of vibration that extends parallel the axis of vibration ofthe first magnet and the axis of vibration of the second magnet andthrough the center of mass of the substrate 102.

The controller 190 can drive the first inductor-magnetic element pair tooscillate the substrate 102 at a first frequency and the secondinductor-second magnetic element 182 pair to oscillate at a similarfrequency in phase with vibration of the first multi-layer inductor 150.Therefore, the first and second multi-layer inductors 150 can cooperateto oscillate the substrate 102 linearly along the overall axis ofvibration. However, the controller 190 can additionally or alternativelydrive the first multi-layer inductor 150 to oscillate the substrate 102at the first frequency and the second multi-layer inductor 150 tooscillate at a second frequency distinct from the first frequency and/orout of phase with vibration of the first multi-layer inductor 150.Therefore, the first and second multi-layer inductors 150 can cooperateto rotate the substrate 102—within a plane parallel the touch sensorsurface 172—about the center of mass.

Additionally or alternatively, the controller 190 can selectively driveeither the first multi-layer inductor 150 or the second multi-layerinductor 150 to oscillate at a particular time. The controller 190 canselectively (and exclusively) drive the first multi-layer inductor 150to mimic a sensation of a click over a section of the substrate 102adjacent the first multi-layer inductor 150. The controller 190 canalternatively drive the second multi-layer inductor 150 to mimic asensation of a click over a section of the substrate 102 adjacent thesecond multi-layer inductor 150 while minimizing vibration over asection of the substrate 102 adjacent the first multi-layer inductor150. For example, the controller 190 can selectively drive the firstmulti-layer inductor 150 to execute the haptic feedback cycle in orderto mimic the sensation of a click on the right side of the substrate 102(or a “right” click) while the second multi-layer inductor 150 remainsinactive.

However, the controller 190 can also drive the first multi-layerinductor 150 to oscillate according to a particular vibration waveform.Simultaneously, the controller 190 can drive the second multi-layerinductor 150 to oscillate according to a vibration waveform out of phase(e.g., 180° out of phase) with the particular vibration waveform of thefirst multi-layer inductor 150. For example, the second multi-layerinductor 150 can output the vibration waveform of an amplitude smallerthan the amplitude of the particular vibration waveform. In thisexample, the vibration waveform of the second multi-layer inductor 150can also be 180° out of phase with the particular vibration waveform ofthe first multi-layer inductor 150. Therefore, the second multi-layerinductor 150 can be configured to counteract (or decrease the amplitudeof) the particular vibration waveform output by the first multi-layerinductor 150.

11. Separate Inductor

In one variation, a region of the substrate 102 is routed or otherwiseremoved to form a shallow recess through a subset of layers of thesubstrate 102. For example, a three-layer-thick region of the substrate102 near the lateral and longitudinal centers of the substrate 102 canbe removed from the bottom face of the substrate 102. A discrete, thin,wire coil can be soldered to a set of vias exposed at a base of therecess and then installed (e.g., bonded, potted) within the recess suchthat the exposed face of the coil is approximately flush (e.g., within100 microns) with the bottom face of the substrate 102.

Additionally or alternatively, the system 100 can include: a firstintegrated inductor fabricated across multiple layers of the substrate102, as described; and a second coil arranged over and electricallycoupled to the first integrated inductor and configured to cooperatewith the first integrated inductor to form a larger inductor exhibitinggreater magnetic coupling to the adjacent magnetic element. For example,the second coil can include: a multi-loop wire coil; or a secondintegrated inductor fabricated across multiple layers of a secondsubstrate 102 that is then bonded and/or soldered to the (first)substrate 102 adjacent the first integrated inductor.

12. Waterproofing

In one variation shown in FIGS. 9A and 9B, a waterproofing membrane 164:is applied over the touch sensor; extends outwardly from the perimeterof the substrate 102; is bonded, clamped, or otherwise retained near aperimeter of the receptacle 194; and thus cooperates with the chassis192 to seal the touch sensor, the substrate 102, and the deflectionspacers 160, etc. within the receptacle 194, thereby preventing moistureand particulate ingress into the receptacle 194 and onto the substrate102.

For example, the waterproofing membrane 164 can include a silicone orPTFE (e.g., expanded PTFE) film bonded over the touch sensor with anadhesive. The system 100 can also include a glass or other cover layer170 bonded over the waterproofing membrane 164 and extending up to aperimeter of the substrate 102.

Furthermore, the chassis 192 can define a flange (or “shelf,” undercut)extending inwardly toward the lateral and longitudinal center of thereceptacle 194. The outer section of the waterproofing member thatextends beyond the substrate 102 can be inserted into the receptacle 194and brought into contact with the underside of the flange. Acircumferential retaining bracket or a secondary chassis 192 member canthen be fastened to the chassis 192 under the flange and (fully) abovethe perimeter of the receptacle 194 in order to clamp the waterproofingmembrane 164 between the chassis 192 and the circumferential retainingbracket or secondary chassis 192 member, thereby sealing thewaterproofing membrane 164 about the receptacle 194.

In one implementation, the waterproofing membrane 164 includes aconvolution between the perimeters of the substrate 102 and thereceptacle 194. In this implementation, the convolution can beconfigured to deflect or deform in order to accommodate oscillation ofthe substrate 102 during a haptic feedback cycle. For example, thewaterproofing membrane 164 can include a polyimide film with asemi-circular ridge extending along a gap between the outer perimeter ofthe substrate 102 and the inner perimeter of the receptacle 194.

In a similar implementation, the substrate 102 and the touch sensor arearranged over the waterproofing membrane 164, which is sealed againstthe chassis 192 along an underside of the receptacle 194 by a retainingbracket, as described above such that the touch sensor assembly islocated fully above a waterproof barrier across the receptacle 194 andsuch that waterproof membrane oscillates to vibrate the touch sensorassembly when the multi-layer inductor 150 is actuated.

The systems and methods described herein can be embodied and/orimplemented at least in part as a machine configured to receive acomputer-readable medium storing computer-readable instructions. Theinstructions can be executed by computer-executable componentsintegrated with the application, applet, host, server, network, website,communication service, communication interface,hardware/firmware/software elements of a user computer or mobile device,wristband, smartphone, or any suitable combination thereof. Othersystems and methods of the embodiment can be embodied and/or implementedat least in part as a machine configured to receive a computer-readablemedium storing computer-readable instructions. The instructions can beexecuted by computer-executable components integrated bycomputer-executable components integrated with apparatuses and networksof the type described above. The computer-readable medium can be storedon any suitable computer readable media such as RAMs, ROMs, flashmemory, EEPROMs, optical devices (CD or DVD), hard drives, floppydrives, or any suitable device. The computer-executable component can bea processor but any suitable dedicated hardware device can(alternatively or additionally) execute the instructions.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the embodiments of the invention without departing fromthe scope of this invention as defined in the following claims.

I claim:
 1. A system comprising: a substrate comprising: a first layercomprising a first spiral trace coiled in a first direction; and asecond layer: arranged below the first inductor layer; and comprising asecond spiral trace: coiled in a second direction opposite the firstdirection; coupled to the first spiral trace; and cooperating with thefirst spiral trace to form a multi-layer inductor; a cover layerarranged over the substrate and defining a touch sensor surface; a firstmagnetic element defining a first polarity facing the multi-layerinductor; and a controller configured to, in response to detecting afirst input on the touch sensor surface, drive an oscillating voltageacross the multi-layer inductor to: induce alternating magnetic couplingbetween the multi-layer inductor and the first magnetic element; andoscillate the substrate and the cover layer relative to first magneticelement.
 2. The system of claim 1: wherein the first spiral tracedefines a first planar coil spiraling inwardly in a clockwise directionwithin the first layer; and wherein the second spiral trace defines asecond planar coil spiraling outwardly in a counter-clockwise directionwithin the second layer and cooperating with the first spiral trace topass current in a common direction about a center of the multi-layerinductor.
 3. The system of claim 1: wherein the first spiral tracedefines a first planar coil spiraling outwardly from a first end to asecond end within the first layer, the second end terminating at aperiphery of the first spiral trace; wherein the second spiral tracedefines a second planar coil spiraling inwardly from a third end to afourth end within the second layer, the fourth end terminating proximala center of the second spiral trace, the third end coupled to the secondend proximal a periphery of the second spiral trace; wherein thecontroller drives the oscillating voltage across the first end of thefirst spiral trace and the fourth end of the second spiral trace inresponse to detecting the first input.
 4. The system of claim 1: whereinthe first spiral trace defines a first end and a second end; wherein thesecond spiral trace defines a third and a fourth end, the third endelectrically coupled to the second end of the first spiral trace;wherein the first layer further comprises a third spiral trace: adjacentthe first spiral trace; coiled in the second direction; and defining afifth end and a sixth end, the fifth end electrically coupled to thefirst end of the first spiral trace; and wherein the second layerfurther comprises a fourth spiral trace: adjacent the second spiraltrace; coiled in the first direction; defining a seventh end and aneighth end, the seventh end electrically coupled to the sixth end of thethird spiral trace; and cooperating with the first spiral trace, thesecond spiral trace, and the third spiral trace to form the multi-layerinductor.
 5. The system of claim 4: further comprising a second magneticelement: arranged adjacent the first magnetic element under the thirdspiral trace and the fourth spiral trace; and defining a secondpolarity, opposite the first polarity; wherein the first magneticelement is arranged under the first spiral trace and the second spiraltrace; and wherein the controller is configured to, in response todetecting the first input, drive the oscillating voltage across thefourth end of the second spiral trace and the eighth end of the fourthspiral trace to: induce alternating magnetic coupling between themulti-layer inductor and the first magnetic element and the secondmagnetic element; and a oscillate the substrate and the cover layerrelative to the first magnetic element and the second magnetic element.6. The system of claim 4: wherein the first magnetic element is arrangedunder the first spiral trace and the second spiral trace; and furthercomprising: a second magnetic element: arranged under the first spiraltrace and the second spiral trace adjacent the first magnetic element;and defining a second polarity facing the multi-layer inductor; and athird magnetic element: arranged under the third spiral trace and thefourth spiral trace adjacent the second magnetic element; and definingthe first polarity facing the multi-layer inductor; and wherein thecontroller is configured to, in response to detecting the first input,drive the oscillating voltage across the fourth end of the second spiraltrace and the eighth end of the fourth spiral trace to: inducealternating magnetic coupling between the first spiral trace, the secondspiral trace, the first magnetic element, and the second magneticelement; induce alternating magnetic coupling between the third spiraltrace, the fourth spiral trace, and the third magnetic element; and aoscillate the substrate and the cover layer parallel to the touch sensorsurface.
 7. The system of claim 1: wherein the substrate furthercomprises: a third inductor layer: arranged below the second inductorlayer opposite the first layer; and comprising a third spiral tracecoiled in the first direction and coupled to the second spiral trace;and a further inductor layer: arranged below the third layer oppositethe second layer; defining a bottom layer of the substrate; andcomprising a fourth spiral trace: coiled in the second direction;coupled to the third spiral trace; and cooperating with the first spiraltrace, the second spiral trace, and the third spiral trace to form themulti-layer inductor; and wherein the controller is configured to, inresponse to detecting the first input, drive the oscillating voltageacross the first spiral trace and the fourth spiral trace to: inducealternating magnetic coupling between the multi-layer inductor and thefirst magnetic element; and oscillate the substrate and the cover layerrelative to the first magnetic element.
 8. The system of claim 1:wherein the first spiral trace defines: a first length along a primaryaxis of the multi-layer inductor coil; and a first width, less than thefirst length, along a secondary axis of the multi-layer inductor coil;wherein the first magnetic element defines: a second length parallel toand offset from the primary axis and approximating the first length; anda second width parallel to the secondary axis and approximately half ofthe first width; and wherein the controller is configured to, inresponse to detecting the first input, drive the oscillating voltageacross the multi-layer inductor to oscillate the substrate and the coverlayer normal to the touch sensor surface.
 9. The system of claim 1:wherein the substrate further comprises a sensor layer comprising a setof drive and sense electrode pairs; wherein the cover layer is arrangedover the sensor layer; and wherein the controller is configured to: readthe set of electrical values, representing capacitive coupling betweendrive and sense electrode pairs, from the set of drive and senseelectrode pairs; and detect the first input at a first location on thetouch sensor surface based on a deviation of a subset of electricalvalues, in the set of electrical values, from baseline capacitancevalues across a subset of drive and sense electrode pairs proximal thefirst location.
 10. The system of claim 9, wherein the substrate furthercomprises an intermediate layer: interposed between the top layer andthe first layer; and comprising a contiguous trace area defining anelectrical shield configured to shield the set of drive and senseelectrode pairs from electrical noise generated by the multi-layerinductor when driven with an oscillating voltage by the controller. 11.The system of claim 1: wherein the substrate further comprises: a toplayer comprising an array of drive and sense electrode pairs arranged ina grid array at a first density; and a bottom layer: arranged below thesecond layer opposite the top layer; and comprising a set of sensortraces located proximal a perimeter of the substrate at a second densityless than the first density; further comprising a set of deflectionspacers coupled to the set of sensor traces and supporting the substrateon a chassis of a device; and wherein the controller is configured to:read the set of electrical values, representing capacitive couplingbetween drive and sense electrode pairs, from the set of drive and senseelectrode pairs; detect the first input at a first location on the touchsensor surface based on a deviation of a subset of electrical values, inthe set of electrical values, from baseline capacitance values across asubset of drive and sense electrode pairs proximal the first location;read a second set of electrical values, representing compression of theset of deflection spacers against the set of sensor traces, from the setof sensor traces; interpret a force magnitude of the first input basedon the second set of electrical values; and drive the oscillatingvoltage across the multi-layer inductor in response to the forcemagnitude of the first input exceeding a threshold input force.
 12. Thesystem of claim 11: wherein the first layer of the substrate furthercomprises a shield electrode trace adjacent and offset from the firstspiral trace; and wherein the controller drives the shield electrodetrace and the first spiral trace to a reference potential to shield thesecond set of sensor traces from electrical noise when reading thesecond set of electrical values from the second set of sensor traces.13. The system of claim 11: wherein each deflection spacer, in the setof deflection spacers, comprises a force-sensitive layer: arrangedacross a sensor trace in the second set of sensor traces; and exhibitingchanges in contact resistance across the sensor trace responsive to aload on the touch sensor surface that compresses the deflection spaceragainst the substrate; and wherein the controller is configured to: readthe second set of electrical values, comprising electrical resistances,from the second set of sensor traces; and interpret the force magnitudeof the first input based on magnitudes of deviations of resistancevalues, in the second set of electrical values, from baseline electricalvalues across the second set of sensor traces.
 14. The system of claim1: wherein the substrate further comprises a sensor layer comprising aset of drive and sense electrode pairs; and wherein the controller isconfigured to: read electrical values from the set of drive and senseelectrode pairs at a scan frequency during a first time period; drivethe oscillating voltage across the multi-layer inductor during a hapticfeedback cycle, following the first time period, in response todetecting the first input based on the set of electrical values readfrom the drive and sense electrode pairs during the first time period;pause reading electrical values from the set of drive and senseelectrode pairs during the haptic feedback cycle; and resume readingelectrical values from the set of drive and sense electrode pairsfollowing completion of the haptic feedback cycle.
 15. The system ofclaim 1: wherein the substrate further comprises a sensor layercomprising a set of drive and sense electrode pairs; and wherein thecontroller is configured to: read electrical values from the set ofdrive and sense electrode pairs at a scan frequency during a first timeperiod; drive the oscillating voltage, at a feedback frequency less thanthe scan frequency, across the multi-layer inductor during a hapticfeedback cycle, following the first time period, in response todetecting the first input based on the set of electrical values readfrom the drive and sense electrode pairs during the first time period;intermittently read electrical values from the set of drive and senseelectrode pairs at the scan frequency, between voltage reversals acrossthe multi-layer inductor at the feedback frequency, during the hapticfeedback cycle; and read electrical values from the set of drive andsense electrode pairs at the scan frequency following completion of thehaptic feedback cycle.
 16. The system of claim 1: further comprising asecond magnetic element defining a second polarity facing themulti-layer inductor; wherein the first magnetic element and the secondmagnetic element are arranged in a cavity within a chassis of a device;and further comprising a set of spring elements: supporting thesubstrate within the cavity with the multi-layer inductor located overthe first magnetic element and the second magnetic element; biasing thesubstrate within the cavity to locate the multi-layer inductor at anominal offset distance above the first magnetic element and the secondmagnetic element; and configured to compress responsive to applicationof the first input on the touch sensor surface to: locate themulti-layer inductor at a second offset distance, less than the nominaloffset distance, above the first magnetic element and the secondmagnetic element; and increase magnetic coupling between the multi-layerinductor, the first magnetic element, and the second magnetic element.17. A system comprising: a substrate comprising: a first set of layerscomprising: a first sensor layer comprising a set of drive and senseelectrode pairs; and a second sensor layer comprising a set of sensortraces; a second set of layers comprising: a first inductor layercomprising a first spiral trace coiled in a first direction; and asecond inductor layer: arranged below the first inductor layer; andcomprising a second spiral trace coiled in a second direction oppositethe first direction and coupled to the first spiral trace to form amulti-layer inductor; a set of deflection spacers coupled to the set ofsensor traces and supporting the substrate on a baseplate; a cover layerarranged over the substrate and defining a touch sensor surface; a firstmagnetic element defining a first polarity facing the multi-layerinductor; and a controller configured to, in response to detecting aforce magnitude of a first input on the touch sensor surface exceeding athreshold force, drive an oscillating voltage across the multi-layerinductor to: induce alternating magnetic coupling between themulti-layer inductor and the first magnetic element; and oscillate thesubstrate and the cover layer relative to first magnetic element. 18.The system of claim 17: wherein the first spiral trace: defines a firstend proximal a perimeter of the first spiral trace; and defines a secondend proximal a center of the first spiral trace; wherein the secondspiral trace: defines a third end proximal a center of the second spiraltrace; and defines a fourth end proximal a perimeter of the secondspiral trace; and wherein the third end of the second spiral trace iscoupled to the second end of the first spiral trace by a via through thefirst layer of the substrate.
 19. A system comprising: a substratecomprising: a set of sensor layers comprising: a first sensor layercomprising a set of drive and sense electrode pairs; and a second sensorlayer arranged below the first sensor layer and comprising a set ofsensor traces; and a set of inductor layers comprising; a first inductorlayer comprising a first spiral trace coiled in a first direction; and asecond inductor layer arranged below the first inductor layer andcomprising a second spiral trace: coiled in a second direction oppositethe first direction; coupled to the first spiral trace; and cooperatingwith the first spiral trace to form a multi-layer inductor; and a coverlayer arranged over the substrate and defining a touch sensor surface.20. The system of claim 19, wherein the set of inductor layers furthercomprises: a third inductor layer: arranged below the second inductorlayer opposite the first layer; and comprising a third spiral tracecoiled in the first direction and coupled to the second spiral trace;and a further inductor layer: arranged below the third layer oppositethe second layer; defining a bottom layer of the substrate; andcomprising a fourth spiral trace: coiled in the second direction;coupled to the third spiral trace; and cooperating with the first spiraltrace, the second spiral trace, and the third spiral trace to form themulti-layer inductor.